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7</head>
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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
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame^]12<div>
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
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame^]56<div>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]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<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]76<h3><a name="concepts">Basic concepts</a></h3>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]77
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame^]78<div>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]79
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]80<p>TableGen files consist of two key parts: 'classes' and 'definitions', both
81of which are considered 'records'.</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]82
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]83<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]84superclasses. The list of values is the main data that TableGen builds for each
85record; it is this that holds the domain specific information for the
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]86application. The interpretation of this data is left to a specific <a
87href="#backends">TableGen backend</a>, but the structure and format rules are
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]88taken care of and are fixed by TableGen.</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]89
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]90<p><b>TableGen definitions</b> are the concrete form of 'records'. These
91generally do not have any undefined values, and are marked with the
92'<tt>def</tt>' keyword.</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]93
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]94<p><b>TableGen classes</b> are abstract records that are used to build and
95describe other records. These 'classes' allow the end-user to build
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]96abstractions for either the domain they are targeting (such as "Register",
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]97"RegisterClass", and "Instruction" in the LLVM code generator) or for the
98implementor to help factor out common properties of records (such as "FPInst",
99which is used to represent floating point instructions in the X86 backend).
100TableGen keeps track of all of the classes that are used to build up a
101definition, so the backend can find all definitions of a particular class, such
102as "Instruction".</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]103
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]104<p><b>TableGen multiclasses</b> are groups of abstract records that are
David Greene753ed8f2009-04-22 16:42:54 +0000[diff] [blame]105instantiated all at once. Each instantiation can result in multiple
106TableGen definitions. If a multiclass inherits from another multiclass,
107the definitions in the sub-multiclass become part of the current
108multiclass, as if they were declared in the current multiclass.</p>
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]109
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]110</div>
111
112<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]113<h3><a name="example">An example record</a></h3>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]114
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame^]115<div>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]116
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]117<p>With no other arguments, TableGen parses the specified file and prints out
118all of the classes, then all of the definitions. This is a good way to see what
119the various definitions expand to fully. Running this on the <tt>X86.td</tt>
120file prints this (at the time of this writing):</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]121
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]122<div class="doc_code">
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]123<pre>
124...
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]125<b>def</b> ADD32rr { <i>// Instruction X86Inst I</i>
Chris Lattner1215e322004-02-06 06:04:25 +0000[diff] [blame]126 <b>string</b> Namespace = "X86";
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]127 <b>dag</b> OutOperandList = (outs GR32:$dst);
128 <b>dag</b> InOperandList = (ins GR32:$src1, GR32:$src2);
129 <b>string</b> AsmString = "add{l}\t{$src2, $dst|$dst, $src2}";
130 <b>list</b>&lt;dag&gt; Pattern = [(set GR32:$dst, (add GR32:$src1, GR32:$src2))];
Chris Lattner1215e322004-02-06 06:04:25 +0000[diff] [blame]131 <b>list</b>&lt;Register&gt; Uses = [];
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]132 <b>list</b>&lt;Register&gt; Defs = [EFLAGS];
133 <b>list</b>&lt;Predicate&gt; Predicates = [];
134 <b>int</b> CodeSize = 3;
135 <b>int</b> AddedComplexity = 0;
Chris Lattner1215e322004-02-06 06:04:25 +0000[diff] [blame]136 <b>bit</b> isReturn = 0;
137 <b>bit</b> isBranch = 0;
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]138 <b>bit</b> isIndirectBranch = 0;
139 <b>bit</b> isBarrier = 0;
Chris Lattner1215e322004-02-06 06:04:25 +0000[diff] [blame]140 <b>bit</b> isCall = 0;
Dan Gohman69cc2cb2008-12-03 18:15:48 +0000[diff] [blame]141 <b>bit</b> canFoldAsLoad = 0;
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]142 <b>bit</b> mayLoad = 0;
143 <b>bit</b> mayStore = 0;
144 <b>bit</b> isImplicitDef = 0;
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]145 <b>bit</b> isConvertibleToThreeAddress = 1;
146 <b>bit</b> isCommutable = 1;
Chris Lattner1215e322004-02-06 06:04:25 +0000[diff] [blame]147 <b>bit</b> isTerminator = 0;
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]148 <b>bit</b> isReMaterializable = 0;
149 <b>bit</b> isPredicable = 0;
150 <b>bit</b> hasDelaySlot = 0;
Dan Gohman453d64c2009-10-29 18:10:34 +0000[diff] [blame]151 <b>bit</b> usesCustomInserter = 0;
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]152 <b>bit</b> hasCtrlDep = 0;
153 <b>bit</b> isNotDuplicable = 0;
154 <b>bit</b> hasSideEffects = 0;
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]155 <b>bit</b> neverHasSideEffects = 0;
156 InstrItinClass Itinerary = NoItinerary;
157 <b>string</b> Constraints = "";
158 <b>string</b> DisableEncoding = "";
159 <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]160 Format Form = MRMDestReg;
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]161 <b>bits</b>&lt;6&gt; FormBits = { 0, 0, 0, 0, 1, 1 };
162 ImmType ImmT = NoImm;
163 <b>bits</b>&lt;3&gt; ImmTypeBits = { 0, 0, 0 };
Chris Lattner1215e322004-02-06 06:04:25 +0000[diff] [blame]164 <b>bit</b> hasOpSizePrefix = 0;
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]165 <b>bit</b> hasAdSizePrefix = 0;
Chris Lattner1215e322004-02-06 06:04:25 +0000[diff] [blame]166 <b>bits</b>&lt;4&gt; Prefix = { 0, 0, 0, 0 };
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]167 <b>bit</b> hasREX_WPrefix = 0;
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]168 FPFormat FPForm = ?;
Chris Lattner1215e322004-02-06 06:04:25 +0000[diff] [blame]169 <b>bits</b>&lt;3&gt; FPFormBits = { 0, 0, 0 };
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]170}
171...
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]172</pre>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]173</div>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]174
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]175<p>This definition corresponds to a 32-bit register-register add instruction in
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]176the X86. The string after the '<tt>def</tt>' string indicates the name of the
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]177record&mdash;"<tt>ADD32rr</tt>" in this case&mdash;and the comment at the end of
178the line indicates the superclasses of the definition. The body of the record
179contains all of the data that TableGen assembled for the record, indicating that
180the instruction is part of the "X86" namespace, the pattern indicating how the
181the instruction should be emitted into the assembly file, that it is a
182two-address instruction, has a particular encoding, etc. The contents and
183semantics of the information in the record is specific to the needs of the X86
184backend, and is only shown as an example.</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]185
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]186<p>As you can see, a lot of information is needed for every instruction
187supported by the code generator, and specifying it all manually would be
Dan Gohman5aa39192010-02-26 02:15:17 +0000[diff] [blame]188unmaintainable, prone to bugs, and tiring to do in the first place. Because we
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]189are using TableGen, all of the information was derived from the following
190definition:</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]191
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]192<div class="doc_code">
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]193<pre>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]194let Defs = [EFLAGS],
195 isCommutable = 1, <i>// X = ADD Y,Z --&gt; X = ADD Z,Y</i>
196 isConvertibleToThreeAddress = 1 <b>in</b> <i>// Can transform into LEA.</i>
197def ADD32rr : I&lt;0x01, MRMDestReg, (outs GR32:$dst),
198 (ins GR32:$src1, GR32:$src2),
199 "add{l}\t{$src2, $dst|$dst, $src2}",
200 [(set GR32:$dst, (add GR32:$src1, GR32:$src2))]&gt;;
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]201</pre>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]202</div>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]203
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]204<p>This definition makes use of the custom class <tt>I</tt> (extended from the
205custom class <tt>X86Inst</tt>), which is defined in the X86-specific TableGen
206file, to factor out the common features that instructions of its class share. A
207key feature of TableGen is that it allows the end-user to define the
208abstractions they prefer to use when describing their information.</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]209
210</div>
211
212<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]213<h3><a name="running">Running TableGen</a></h3>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]214
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame^]215<div>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]216
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]217<p>TableGen runs just like any other LLVM tool. The first (optional) argument
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]218specifies the file to read. If a filename is not specified, <tt>tblgen</tt>
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]219reads from standard input.</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]220
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]221<p>To be useful, one of the <a href="#backends">TableGen backends</a> must be
222used. These backends are selectable on the command line (type '<tt>tblgen
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]223-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]224that subclass a particular type (which can be useful for building up an enum
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]225list of these records), use the <tt>-print-enums</tt> option:</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]226
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]227<div class="doc_code">
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]228<pre>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]229$ tblgen X86.td -print-enums -class=Register
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]230AH, AL, AX, BH, BL, BP, BPL, BX, CH, CL, CX, DH, DI, DIL, DL, DX, EAX, EBP, EBX,
231ECX, EDI, EDX, EFLAGS, EIP, ESI, ESP, FP0, FP1, FP2, FP3, FP4, FP5, FP6, IP,
232MM0, MM1, MM2, MM3, MM4, MM5, MM6, MM7, R10, R10B, R10D, R10W, R11, R11B, R11D,
233R11W, R12, R12B, R12D, R12W, R13, R13B, R13D, R13W, R14, R14B, R14D, R14W, R15,
234R15B, R15D, R15W, R8, R8B, R8D, R8W, R9, R9B, R9D, R9W, RAX, RBP, RBX, RCX, RDI,
235RDX, RIP, RSI, RSP, SI, SIL, SP, SPL, ST0, ST1, ST2, ST3, ST4, ST5, ST6, ST7,
236XMM0, XMM1, XMM10, XMM11, XMM12, XMM13, XMM14, XMM15, XMM2, XMM3, XMM4, XMM5,
237XMM6, XMM7, XMM8, XMM9,
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]238
239$ tblgen X86.td -print-enums -class=Instruction
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]240ABS_F, ABS_Fp32, ABS_Fp64, ABS_Fp80, ADC32mi, ADC32mi8, ADC32mr, ADC32ri,
241ADC32ri8, ADC32rm, ADC32rr, ADC64mi32, ADC64mi8, ADC64mr, ADC64ri32, ADC64ri8,
242ADC64rm, ADC64rr, ADD16mi, ADD16mi8, ADD16mr, ADD16ri, ADD16ri8, ADD16rm,
243ADD16rr, ADD32mi, ADD32mi8, ADD32mr, ADD32ri, ADD32ri8, ADD32rm, ADD32rr,
244ADD64mi32, ADD64mi8, ADD64mr, ADD64ri32, ...
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]245</pre>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]246</div>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]247
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]248<p>The default backend prints out all of the records, as described <a
249href="#example">above</a>.</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]250
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]251<p>If you plan to use TableGen, you will most likely have to <a
252href="#backends">write a backend</a> that extracts the information specific to
253what you need and formats it in the appropriate way.</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]254
255</div>
256
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame^]257</div>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]258
259<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]260<h2><a name="syntax">TableGen syntax</a></h2>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]261<!-- *********************************************************************** -->
262
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame^]263<div>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]264
265<p>TableGen doesn't care about the meaning of data (that is up to the backend to
266define), but it does care about syntax, and it enforces a simple type system.
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]267This section describes the syntax and the constructs allowed in a TableGen file.
268</p>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]269
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]270<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]271<h3><a name="primitives">TableGen primitives</a></h3>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]272
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame^]273<div>
274
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]275<!-- -------------------------------------------------------------------------->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]276<h4><a name="comments">TableGen comments</a></h4>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]277
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame^]278<div>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]279
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]280<p>TableGen supports BCPL style "<tt>//</tt>" comments, which run to the end of
281the line, and it also supports <b>nestable</b> "<tt>/* */</tt>" comments.</p>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]282
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]283</div>
284
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]285<!-- -------------------------------------------------------------------------->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]286<h4>
Misha Brukman94192b62004-06-03 16:59:59 +0000[diff] [blame]287 <a name="types">The TableGen type system</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]288</h4>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]289
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame^]290<div>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]291
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]292<p>TableGen files are strongly typed, in a simple (but complete) type-system.
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]293These types are used to perform automatic conversions, check for errors, and to
294help interface designers constrain the input that they allow. Every <a
295href="#valuedef">value definition</a> is required to have an associated type.
296</p>
297
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]298<p>TableGen supports a mixture of very low-level types (such as <tt>bit</tt>)
299and very high-level types (such as <tt>dag</tt>). This flexibility is what
300allows it to describe a wide range of information conveniently and compactly.
301The TableGen types are:</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]302
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]303<dl>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]304<dt><tt><b>bit</b></tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]305 <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]306
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]307<dt><tt><b>int</b></tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]308 <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]309
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]310<dt><tt><b>string</b></tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]311 <dd>The 'string' type represents an ordered sequence of characters of
312 arbitrary length.</dd>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]313
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]314<dt><tt><b>bits</b>&lt;n&gt;</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]315 <dd>A 'bits' type is an arbitrary, but fixed, size integer that is broken up
316 into individual bits. This type is useful because it can handle some bits
317 being defined while others are undefined.</dd>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]318
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]319<dt><tt><b>list</b>&lt;ty&gt;</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]320 <dd>This type represents a list whose elements are some other type. The
321 contained type is arbitrary: it can even be another list type.</dd>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]322
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]323<dt>Class type</dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]324 <dd>Specifying a class name in a type context means that the defined value
325 must be a subclass of the specified class. This is useful in conjunction with
326 the <b><tt>list</tt></b> type, for example, to constrain the elements of the
327 list to a common base class (e.g., a <tt><b>list</b>&lt;Register&gt;</tt> can
328 only contain definitions derived from the "<tt>Register</tt>" class).</dd>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]329
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]330<dt><tt><b>dag</b></tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]331 <dd>This type represents a nestable directed graph of elements.</dd>
332
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]333<dt><tt><b>code</b></tt></dt>
Chris Lattner28175bf2010-04-22 16:45:27 +0000[diff] [blame]334 <dd>This represents a big hunk of text. This is lexically distinct from
335 string values because it doesn't require escapeing double quotes and other
336 common characters that occur in code.</dd>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]337</dl>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]338
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]339<p>To date, these types have been sufficient for describing things that
340TableGen has been used for, but it is straight-forward to extend this list if
341needed.</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]342
343</div>
344
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]345<!-- -------------------------------------------------------------------------->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]346<h4>
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]347 <a name="values">TableGen values and expressions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]348</h4>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]349
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame^]350<div>
Misha Brukman94192b62004-06-03 16:59:59 +0000[diff] [blame]351
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]352<p>TableGen allows for a pretty reasonable number of different expression forms
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]353when building up values. These forms allow the TableGen file to be written in a
354natural syntax and flavor for the application. The current expression forms
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]355supported include:</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]356
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]357<dl>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]358<dt><tt>?</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]359 <dd>uninitialized field</dd>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]360<dt><tt>0b1001011</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]361 <dd>binary integer value</dd>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]362<dt><tt>07654321</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]363 <dd>octal integer value (indicated by a leading 0)</dd>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]364<dt><tt>7</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]365 <dd>decimal integer value</dd>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]366<dt><tt>0x7F</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]367 <dd>hexadecimal integer value</dd>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]368<dt><tt>"foo"</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]369 <dd>string value</dd>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]370<dt><tt>[{ ... }]</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]371 <dd>code fragment</dd>
Benjamin Kramereaccdd32009-08-05 15:42:44 +0000[diff] [blame]372<dt><tt>[ X, Y, Z ]&lt;type&gt;</tt></dt>
373 <dd>list value. &lt;type&gt; is the type of the list
David Greene26433c22009-06-08 22:38:07 +0000[diff] [blame]374element and is usually optional. In rare cases,
375TableGen is unable to deduce the element type in
376which case the user must specify it explicitly.</dd>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]377<dt><tt>{ a, b, c }</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]378 <dd>initializer for a "bits&lt;3&gt;" value</dd>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]379<dt><tt>value</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]380 <dd>value reference</dd>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]381<dt><tt>value{17}</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]382 <dd>access to one bit of a value</dd>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]383<dt><tt>value{15-17}</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]384 <dd>access to multiple bits of a value</dd>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]385<dt><tt>DEF</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]386 <dd>reference to a record definition</dd>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]387<dt><tt>CLASS&lt;val list&gt;</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]388 <dd>reference to a new anonymous definition of CLASS with the specified
389 template arguments.</dd>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]390<dt><tt>X.Y</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]391 <dd>reference to the subfield of a value</dd>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]392<dt><tt>list[4-7,17,2-3]</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]393 <dd>A slice of the 'list' list, including elements 4,5,6,7,17,2, and 3 from
394 it. Elements may be included multiple times.</dd>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]395<dt><tt>(DEF a, b)</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]396 <dd>a dag value. The first element is required to be a record definition, the
397 remaining elements in the list may be arbitrary other values, including nested
398 `<tt>dag</tt>' values.</dd>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]399<dt><tt>!strconcat(a, b)</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]400 <dd>A string value that is the result of concatenating the 'a' and 'b'
401 strings.</dd>
Benjamin Kramereaccdd32009-08-05 15:42:44 +0000[diff] [blame]402<dt><tt>!cast&lt;type&gt;(a)</tt></dt>
David Greenee8f3b272009-05-14 21:22:49 +0000[diff] [blame]403 <dd>A symbol of type <em>type</em> obtained by looking up the string 'a' in
404the symbol table. If the type of 'a' does not match <em>type</em>, TableGen
Benjamin Kramereaccdd32009-08-05 15:42:44 +0000[diff] [blame]405aborts 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]406be an object defined by a 'def' construct.</dd>
David Greene98ed3c72009-05-14 21:54:42 +0000[diff] [blame]407<dt><tt>!subst(a, b, c)</tt></dt>
408 <dd>If 'a' and 'b' are of string type or are symbol references, substitute
409'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]410<dt><tt>!foreach(a, b, c)</tt></dt>
411 <dd>For each member 'b' of dag or list 'a' apply operator 'c.' 'b' is a
412dummy variable that should be declared as a member variable of an instantiated
413class. This operation is analogous to $(foreach) in GNU make.</dd>
David Greene2f7cf7f2011-01-07 17:05:37 +0000[diff] [blame]414<dt><tt>!head(a)</tt></dt>
David Greened571b3c2009-05-14 22:38:31 +0000[diff] [blame]415 <dd>The first element of list 'a.'</dd>
David Greene2f7cf7f2011-01-07 17:05:37 +0000[diff] [blame]416<dt><tt>!tail(a)</tt></dt>
David Greened571b3c2009-05-14 22:38:31 +0000[diff] [blame]417 <dd>The 2nd-N elements of list 'a.'</dd>
David Greene2f7cf7f2011-01-07 17:05:37 +0000[diff] [blame]418<dt><tt>!empty(a)</tt></dt>
David Greened571b3c2009-05-14 22:38:31 +0000[diff] [blame]419 <dd>An integer {0,1} indicating whether list 'a' is empty.</dd>
David Greene3587eed2009-05-14 23:26:46 +0000[diff] [blame]420<dt><tt>!if(a,b,c)</tt></dt>
Bruno Cardoso Lopes4d1d7982010-06-17 00:31:36 +0000[diff] [blame]421 <dd>'b' if the result of 'int' or 'bit' operator 'a' is nonzero,
422 'c' otherwise.</dd>
David Greene297bfe62010-01-05 19:11:42 +0000[diff] [blame]423<dt><tt>!eq(a,b)</tt></dt>
Chris Lattner7ff33462010-10-31 19:22:57 +0000[diff] [blame]424 <dd>'bit 1' if string a is equal to string b, 0 otherwise. This
Benjamin Kramerc940bcf2010-10-30 21:07:28 +0000[diff] [blame]425 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]426 compare other types of objects.</dd>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]427</dl>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]428
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]429<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]430for different types. These rules allow you to assign a value like "<tt>7</tt>"
431to a "<tt>bits&lt;4&gt;</tt>" value, for example.</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]432
433</div>
434
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame^]435</div>
436
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]437<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]438<h3>
Misha Brukman94192b62004-06-03 16:59:59 +0000[diff] [blame]439 <a name="classesdefs">Classes and definitions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]440</h3>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]441
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame^]442<div>
Misha Brukman94192b62004-06-03 16:59:59 +0000[diff] [blame]443
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]444<p>As mentioned in the <a href="#concepts">intro</a>, classes and definitions
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]445(collectively known as 'records') in TableGen are the main high-level unit of
446information that TableGen collects. Records are defined with a <tt>def</tt> or
447<tt>class</tt> keyword, the record name, and an optional list of "<a
Misha Brukman31551592004-06-03 23:42:24 +0000[diff] [blame]448href="#templateargs">template arguments</a>". If the record has superclasses,
Jeff Cohendd24d7c2005-10-24 16:54:55 +0000[diff] [blame]449they are specified as a comma separated list that starts with a colon character
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]450("<tt>:</tt>"). If <a href="#valuedef">value definitions</a> or <a
451href="#recordlet">let expressions</a> are needed for the class, they are
452enclosed in curly braces ("<tt>{}</tt>"); otherwise, the record ends with a
453semicolon.</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]454
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]455<p>Here is a simple TableGen file:</p>
456
457<div class="doc_code">
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]458<pre>
Chris Lattner1215e322004-02-06 06:04:25 +0000[diff] [blame]459<b>class</b> C { <b>bit</b> V = 1; }
460<b>def</b> X : C;
461<b>def</b> Y : C {
462 <b>string</b> Greeting = "hello";
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]463}
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]464</pre>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]465</div>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]466
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]467<p>This example defines two definitions, <tt>X</tt> and <tt>Y</tt>, both of
468which derive from the <tt>C</tt> class. Because of this, they both get the
469<tt>V</tt> bit value. The <tt>Y</tt> definition also gets the Greeting member
470as well.</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]471
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]472<p>In general, classes are useful for collecting together the commonality
473between a group of records and isolating it in a single place. Also, classes
474permit the specification of default values for their subclasses, allowing the
475subclasses to override them as they wish.</p>
Chris Lattner55927232004-02-06 06:37:00 +0000[diff] [blame]476
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]477<!---------------------------------------------------------------------------->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]478<h4>
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]479 <a name="valuedef">Value definitions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]480</h4>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]481
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame^]482<div>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]483
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]484<p>Value definitions define named entries in records. A value must be defined
John Criswell407f6d42004-02-12 18:11:53 +0000[diff] [blame]485before it can be referred to as the operand for another value definition or
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]486before the value is reset with a <a href="#recordlet">let expression</a>. A
487value is defined by specifying a <a href="#types">TableGen type</a> and a name.
488If an initial value is available, it may be specified after the type with an
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]489equal sign. Value definitions require terminating semicolons.</p>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]490
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]491</div>
492
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]493<!-- -------------------------------------------------------------------------->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]494<h4>
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]495 <a name="recordlet">'let' expressions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]496</h4>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]497
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame^]498<div>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]499
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]500<p>A record-level let expression is used to change the value of a value
501definition in a record. This is primarily useful when a superclass defines a
502value that a derived class or definition wants to override. Let expressions
503consist of the '<tt>let</tt>' keyword followed by a value name, an equal sign
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]504("<tt>=</tt>"), and a new value. For example, a new class could be added to the
505example above, redefining the <tt>V</tt> field for all of its subclasses:</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]506
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]507<div class="doc_code">
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]508<pre>
Chris Lattner1215e322004-02-06 06:04:25 +0000[diff] [blame]509<b>class</b> D : C { let V = 0; }
510<b>def</b> Z : D;
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]511</pre>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]512</div>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]513
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]514<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]515value, despite the fact that it derives (indirectly) from the <tt>C</tt> class,
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]516because the <tt>D</tt> class overrode its value.</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]517
518</div>
519
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]520<!-- -------------------------------------------------------------------------->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]521<h4>
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]522 <a name="templateargs">Class template arguments</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]523</h4>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]524
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame^]525<div>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]526
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]527<p>TableGen permits the definition of parameterized classes as well as normal
Chris Lattner55927232004-02-06 06:37:00 +0000[diff] [blame]528concrete classes. Parameterized TableGen classes specify a list of variable
529bindings (which may optionally have defaults) that are bound when used. Here is
530a simple example:</p>
531
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]532<div class="doc_code">
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]533<pre>
Chris Lattner55927232004-02-06 06:37:00 +0000[diff] [blame]534<b>class</b> FPFormat&lt;<b>bits</b>&lt;3&gt; val&gt; {
535 <b>bits</b>&lt;3&gt; Value = val;
536}
537<b>def</b> NotFP : FPFormat&lt;0&gt;;
538<b>def</b> ZeroArgFP : FPFormat&lt;1&gt;;
539<b>def</b> OneArgFP : FPFormat&lt;2&gt;;
540<b>def</b> OneArgFPRW : FPFormat&lt;3&gt;;
541<b>def</b> TwoArgFP : FPFormat&lt;4&gt;;
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]542<b>def</b> CompareFP : FPFormat&lt;5&gt;;
543<b>def</b> CondMovFP : FPFormat&lt;6&gt;;
544<b>def</b> SpecialFP : FPFormat&lt;7&gt;;
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]545</pre>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]546</div>
Chris Lattner55927232004-02-06 06:37:00 +0000[diff] [blame]547
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]548<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]549a list of "enumeration values", each with a "<tt>Value</tt>" field set to the
550specified integer.</p>
Chris Lattner55927232004-02-06 06:37:00 +0000[diff] [blame]551
552<p>The more esoteric forms of <a href="#values">TableGen expressions</a> are
553useful in conjunction with template arguments. As an example:</p>
554
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]555<div class="doc_code">
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]556<pre>
Chris Lattner55927232004-02-06 06:37:00 +0000[diff] [blame]557<b>class</b> ModRefVal&lt;<b>bits</b>&lt;2&gt; val&gt; {
558 <b>bits</b>&lt;2&gt; Value = val;
559}
560
561<b>def</b> None : ModRefVal&lt;0&gt;;
562<b>def</b> Mod : ModRefVal&lt;1&gt;;
563<b>def</b> Ref : ModRefVal&lt;2&gt;;
564<b>def</b> ModRef : ModRefVal&lt;3&gt;;
565
566<b>class</b> Value&lt;ModRefVal MR&gt; {
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]567 <i>// Decode some information into a more convenient format, while providing
Chris Lattner55927232004-02-06 06:37:00 +0000[diff] [blame]568 // a nice interface to the user of the "Value" class.</i>
569 <b>bit</b> isMod = MR.Value{0};
570 <b>bit</b> isRef = MR.Value{1};
571
572 <i>// other stuff...</i>
573}
574
575<i>// Example uses</i>
576<b>def</b> bork : Value&lt;Mod&gt;;
577<b>def</b> zork : Value&lt;Ref&gt;;
578<b>def</b> hork : Value&lt;ModRef&gt;;
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]579</pre>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]580</div>
Chris Lattner55927232004-02-06 06:37:00 +0000[diff] [blame]581
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]582<p>This is obviously a contrived example, but it shows how template arguments
583can 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]584actual internal data representation expected by the class. In this case,
585running <tt>tblgen</tt> on the example prints the following definitions:</p>
586
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]587<div class="doc_code">
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]588<pre>
Chris Lattner55927232004-02-06 06:37:00 +0000[diff] [blame]589<b>def</b> bork { <i>// Value</i>
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]590 <b>bit</b> isMod = 1;
591 <b>bit</b> isRef = 0;
Chris Lattner55927232004-02-06 06:37:00 +0000[diff] [blame]592}
593<b>def</b> hork { <i>// Value</i>
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]594 <b>bit</b> isMod = 1;
595 <b>bit</b> isRef = 1;
Chris Lattner55927232004-02-06 06:37:00 +0000[diff] [blame]596}
597<b>def</b> zork { <i>// Value</i>
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]598 <b>bit</b> isMod = 0;
599 <b>bit</b> isRef = 1;
Chris Lattner55927232004-02-06 06:37:00 +0000[diff] [blame]600}
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]601</pre>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]602</div>
Chris Lattner55927232004-02-06 06:37:00 +0000[diff] [blame]603
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]604<p> This shows that TableGen was able to dig into the argument and extract a
605piece of information that was requested by the designer of the "Value" class.
606For more realistic examples, please see existing users of TableGen, such as the
607X86 backend.</p>
Chris Lattner55927232004-02-06 06:37:00 +0000[diff] [blame]608
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]609</div>
610
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]611<!-- -------------------------------------------------------------------------->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]612<h4>
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]613 <a name="multiclass">Multiclass definitions and instances</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]614</h4>
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]615
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame^]616<div>
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]617
618<p>
619While classes with template arguments are a good way to factor commonality
620between two instances of a definition, multiclasses allow a convenient notation
621for defining multiple definitions at once (instances of implicitly constructed
622classes). For example, consider an 3-address instruction set whose instructions
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]623come in two forms: "<tt>reg = reg op reg</tt>" and "<tt>reg = reg op imm</tt>"
624(e.g. SPARC). In this case, you'd like to specify in one place that this
625commonality exists, then in a separate place indicate what all the ops are.
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]626</p>
627
628<p>
629Here is an example TableGen fragment that shows this idea:
630</p>
631
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]632<div class="doc_code">
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]633<pre>
634<b>def</b> ops;
635<b>def</b> GPR;
636<b>def</b> Imm;
637<b>class</b> inst&lt;<b>int</b> opc, <b>string</b> asmstr, <b>dag</b> operandlist&gt;;
638
639<b>multiclass</b> ri_inst&lt;<b>int</b> opc, <b>string</b> asmstr&gt; {
640 def _rr : inst&lt;opc, !strconcat(asmstr, " $dst, $src1, $src2"),
641 (ops GPR:$dst, GPR:$src1, GPR:$src2)&gt;;
642 def _ri : inst&lt;opc, !strconcat(asmstr, " $dst, $src1, $src2"),
643 (ops GPR:$dst, GPR:$src1, Imm:$src2)&gt;;
644}
645
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]646<i>// Instantiations of the ri_inst multiclass.</i>
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]647<b>defm</b> ADD : ri_inst&lt;0b111, "add"&gt;;
648<b>defm</b> SUB : ri_inst&lt;0b101, "sub"&gt;;
649<b>defm</b> MUL : ri_inst&lt;0b100, "mul"&gt;;
650...
651</pre>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]652</div>
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]653
Chris Lattner28368122006-09-01 22:01:36 +0000[diff] [blame]654<p>The name of the resultant definitions has the multidef fragment names
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]655 appended to them, so this defines <tt>ADD_rr</tt>, <tt>ADD_ri</tt>,
David Greenef00919a2009-04-22 22:17:51 +0000[diff] [blame]656 <tt>SUB_rr</tt>, etc. A defm may inherit from multiple multiclasses,
657 instantiating definitions from each multiclass. Using a multiclass
658 this way is exactly equivalent to instantiating the classes multiple
659 times yourself, e.g. by writing:</p>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]660
661<div class="doc_code">
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]662<pre>
663<b>def</b> ops;
664<b>def</b> GPR;
665<b>def</b> Imm;
666<b>class</b> inst&lt;<b>int</b> opc, <b>string</b> asmstr, <b>dag</b> operandlist&gt;;
667
668<b>class</b> rrinst&lt;<b>int</b> opc, <b>string</b> asmstr&gt;
669 : inst&lt;opc, !strconcat(asmstr, " $dst, $src1, $src2"),
670 (ops GPR:$dst, GPR:$src1, GPR:$src2)&gt;;
671
672<b>class</b> riinst&lt;<b>int</b> opc, <b>string</b> asmstr&gt;
673 : inst&lt;opc, !strconcat(asmstr, " $dst, $src1, $src2"),
674 (ops GPR:$dst, GPR:$src1, Imm:$src2)&gt;;
675
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]676<i>// Instantiations of the ri_inst multiclass.</i>
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]677<b>def</b> ADD_rr : rrinst&lt;0b111, "add"&gt;;
678<b>def</b> ADD_ri : riinst&lt;0b111, "add"&gt;;
679<b>def</b> SUB_rr : rrinst&lt;0b101, "sub"&gt;;
680<b>def</b> SUB_ri : riinst&lt;0b101, "sub"&gt;;
681<b>def</b> MUL_rr : rrinst&lt;0b100, "mul"&gt;;
682<b>def</b> MUL_ri : riinst&lt;0b100, "mul"&gt;;
683...
684</pre>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]685</div>
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]686
Bruno Cardoso Lopesc4f61482010-06-05 02:11:52 +0000[diff] [blame]687<p>
688A defm can also be used inside a multiclass providing several levels of
689multiclass instanciations.
690</p>
691
692<div class="doc_code">
693<pre>
694<b>class</b> Instruction&lt;bits&lt;4&gt; opc, string Name&gt; {
695 bits&lt;4&gt; opcode = opc;
696 string name = Name;
697}
698
699<b>multiclass</b> basic_r&lt;bits&lt;4&gt; opc&gt; {
700 <b>def</b> rr : Instruction&lt;opc, "rr"&gt;;
701 <b>def</b> rm : Instruction&lt;opc, "rm"&gt;;
702}
703
704<b>multiclass</b> basic_s&lt;bits&lt;4&gt; opc&gt; {
705 <b>defm</b> SS : basic_r&lt;opc&gt;;
706 <b>defm</b> SD : basic_r&lt;opc&gt;;
707 <b>def</b> X : Instruction&lt;opc, "x"&gt;;
708}
709
710<b>multiclass</b> basic_p&lt;bits&lt;4&gt; opc&gt; {
711 <b>defm</b> PS : basic_r&lt;opc&gt;;
712 <b>defm</b> PD : basic_r&lt;opc&gt;;
713 <b>def</b> Y : Instruction&lt;opc, "y"&gt;;
714}
715
716<b>defm</b> ADD : basic_s&lt;0xf&gt;, basic_p&lt;0xf&gt;;
717...
718
719<i>// Results</i>
720<b>def</b> ADDPDrm { ...
721<b>def</b> ADDPDrr { ...
722<b>def</b> ADDPSrm { ...
723<b>def</b> ADDPSrr { ...
724<b>def</b> ADDSDrm { ...
725<b>def</b> ADDSDrr { ...
726<b>def</b> ADDY { ...
727<b>def</b> ADDX { ...
728</pre>
729</div>
730
Bruno Cardoso Lopes23f83212010-06-18 19:53:41 +0000[diff] [blame]731<p>
732defm declarations can inherit from classes too, the
733rule to follow is that the class list must start after the
734last multiclass, and there must be at least one multiclass
735before them.
736</p>
737
738<div class="doc_code">
739<pre>
740<b>class</b> XD { bits&lt;4&gt; Prefix = 11; }
741<b>class</b> XS { bits&lt;4&gt; Prefix = 12; }
742
743<b>class</b> I&lt;bits<4&gt; op> {
744 bits&lt;4&gt; opcode = op;
745}
746
747<b>multiclass</b> R {
748 <b>def</b> rr : I&lt;4&gt;;
749 <b>def</b> rm : I&lt;2&gt;;
750}
751
752<b>multiclass</b> Y {
753 <b>defm</b> SS : R, XD;
754 <b>defm</b> SD : R, XS;
755}
756
757<b>defm</b> Instr : Y;
758
759<i>// Results</i>
760<b>def</b> InstrSDrm {
761 bits&lt;4&gt; opcode = { 0, 0, 1, 0 };
762 bits&lt;4&gt; Prefix = { 1, 1, 0, 0 };
763}
764...
765<b>def</b> InstrSSrr {
766 bits&lt;4&gt; opcode = { 0, 1, 0, 0 };
767 bits&lt;4&gt; Prefix = { 1, 0, 1, 1 };
768}
769</pre>
770</div>
771
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]772</div>
773
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame^]774</div>
775
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]776<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]777<h3>
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]778 <a name="filescope">File scope entities</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]779</h3>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]780
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame^]781<div>
782
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]783<!-- -------------------------------------------------------------------------->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]784<h4>
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]785 <a name="include">File inclusion</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]786</h4>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]787
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame^]788<div>
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]789<p>TableGen supports the '<tt>include</tt>' token, which textually substitutes
790the specified file in place of the include directive. The filename should be
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]791specified as a double quoted string immediately after the '<tt>include</tt>'
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]792keyword. Example:</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]793
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]794<div class="doc_code">
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]795<pre>
Chris Lattner55927232004-02-06 06:37:00 +0000[diff] [blame]796<b>include</b> "foo.td"
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]797</pre>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]798</div>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]799
800</div>
801
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]802<!-- -------------------------------------------------------------------------->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]803<h4>
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]804 <a name="globallet">'let' expressions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]805</h4>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]806
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame^]807<div>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]808
809<p>"Let" expressions at file scope are similar to <a href="#recordlet">"let"
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]810expressions within a record</a>, except they can specify a value binding for
811multiple records at a time, and may be useful in certain other cases.
812File-scope let expressions are really just another way that TableGen allows the
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]813end-user to factor out commonality from the records.</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]814
Jeff Cohendd24d7c2005-10-24 16:54:55 +0000[diff] [blame]815<p>File-scope "let" expressions take a comma-separated list of bindings to
Matthijs Kooijman3abb3082008-10-20 08:45:34 +0000[diff] [blame]816apply, and one or more records to bind the values in. Here are some
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]817examples:</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]818
Bill Wendling7a05f002010-12-08 02:46:25 +0000[diff] [blame]819<div class="doc_code">
820<pre>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]821<b>let</b> isTerminator = 1, isReturn = 1, isBarrier = 1, hasCtrlDep = 1 <b>in</b>
822 <b>def</b> RET : I&lt;0xC3, RawFrm, (outs), (ins), "ret", [(X86retflag 0)]&gt;;
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]823
Chris Lattner1215e322004-02-06 06:04:25 +0000[diff] [blame]824<b>let</b> isCall = 1 <b>in</b>
825 <i>// All calls clobber the non-callee saved registers...</i>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]826 <b>let</b> Defs = [EAX, ECX, EDX, FP0, FP1, FP2, FP3, FP4, FP5, FP6, ST0,
827 MM0, MM1, MM2, MM3, MM4, MM5, MM6, MM7,
828 XMM0, XMM1, XMM2, XMM3, XMM4, XMM5, XMM6, XMM7, EFLAGS] <b>in</b> {
Dan Gohman2ed27532008-10-14 17:00:38 +0000[diff] [blame]829 <b>def</b> CALLpcrel32 : Ii32&lt;0xE8, RawFrm, (outs), (ins i32imm:$dst,variable_ops),
830 "call\t${dst:call}", []&gt;;
831 <b>def</b> CALL32r : I&lt;0xFF, MRM2r, (outs), (ins GR32:$dst, variable_ops),
832 "call\t{*}$dst", [(X86call GR32:$dst)]&gt;;
833 <b>def</b> CALL32m : I&lt;0xFF, MRM2m, (outs), (ins i32mem:$dst, variable_ops),
834 "call\t{*}$dst", []&gt;;
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]835 }
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]836</pre>
Bill Wendling7a05f002010-12-08 02:46:25 +0000[diff] [blame]837</div>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]838
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]839<p>File-scope "let" expressions are often useful when a couple of definitions
840need 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]841opened, as in the case with the <tt>CALL*</tt> instructions above.</p>
842
Bruno Cardoso Lopes5f2adcc2010-06-10 02:42:59 +0000[diff] [blame]843<p>It's also possible to use "let" expressions inside multiclasses, providing
844more ways to factor out commonality from the records, specially if using
845several levels of multiclass instanciations. This also avoids the need of using
846"let" expressions within subsequent records inside a multiclass.</p>
847
Benjamin Kramerc940bcf2010-10-30 21:07:28 +0000[diff] [blame]848<pre class="doc_code">
Bruno Cardoso Lopes5f2adcc2010-06-10 02:42:59 +0000[diff] [blame]849<b>multiclass </b>basic_r&lt;bits&lt;4&gt; opc&gt; {
850 <b>let </b>Predicates = [HasSSE2] in {
851 <b>def </b>rr : Instruction&lt;opc, "rr"&gt;;
852 <b>def </b>rm : Instruction&lt;opc, "rm"&gt;;
853 }
854 <b>let </b>Predicates = [HasSSE3] in
855 <b>def </b>rx : Instruction&lt;opc, "rx"&gt;;
856}
857
858<b>multiclass </b>basic_ss&lt;bits&lt;4&gt; opc&gt; {
859 <b>let </b>IsDouble = 0 in
860 <b>defm </b>SS : basic_r&lt;opc&gt;;
861
862 <b>let </b>IsDouble = 1 in
863 <b>defm </b>SD : basic_r&lt;opc&gt;;
864}
865
866<b>defm </b>ADD : basic_ss&lt;0xf&gt;;
867</pre>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]868</div>
869
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame^]870</div>
871
872</div>
873
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]874<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]875<h2><a name="codegen">Code Generator backend info</a></h2>
Evan Chengef716b02009-10-05 02:51:06 +0000[diff] [blame]876<!-- *********************************************************************** -->
877
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame^]878<div>
Benjamin Kramerc940bcf2010-10-30 21:07:28 +0000[diff] [blame]879
Evan Chengef716b02009-10-05 02:51:06 +0000[diff] [blame]880<p>Expressions used by code generator to describe instructions and isel
881patterns:</p>
882
Benjamin Kramerc940bcf2010-10-30 21:07:28 +0000[diff] [blame]883<dl>
Evan Chengef716b02009-10-05 02:51:06 +0000[diff] [blame]884<dt><tt>(implicit a)</tt></dt>
885 <dd>an implicitly defined physical register. This tells the dag instruction
886 selection emitter the input pattern's extra definitions matches implicit
887 physical register definitions.</dd>
Benjamin Kramerc940bcf2010-10-30 21:07:28 +0000[diff] [blame]888</dl>
Evan Chengef716b02009-10-05 02:51:06 +0000[diff] [blame]889</div>
890
891<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]892<h2><a name="backends">TableGen backends</a></h2>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]893<!-- *********************************************************************** -->
894
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame^]895<div>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]896
897<p>TODO: How they work, how to write one. This section should not contain
898details about any particular backend, except maybe -print-enums as an example.
899This should highlight the APIs in <tt>TableGen/Record.h</tt>.</p>
900
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]901</div>
902
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]903<!-- *********************************************************************** -->
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]904
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]905<hr>
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]906<address>
907 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]908 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
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Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]911
912 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumica46f5a2011-04-09 02:13:37 +0000[diff] [blame]913 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]914 Last modified: $Date$
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]915</address>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]916
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