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gerrit-public.fairphone.software / fp2-dev / platform / external / llvm / 40230c4c06e0ad1afbef217229363cab077368b3 / . / docs / TableGenFundamentals.html
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5 <title>TableGen Fundamentals</title>
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7</head>
8<body>
9
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]10<h1>TableGen Fundamentals</h1>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]11
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]12<div>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]13<ul>
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]14 <li><a href="#introduction">Introduction</a>
Chris Lattnerb54c99c2004-02-06 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 Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]19 </ol></li>
20 <li><a href="#syntax">TableGen syntax</a>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]21 <ol>
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]22 <li><a href="#primitives">TableGen primitives</a>
Chris Lattnerb54c99c2004-02-06 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 Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]27 </ol></li>
28 <li><a href="#classesdefs">Classes and definitions</a>
Chris Lattnerb54c99c2004-02-06 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 Lattner84b35982006-09-01 21:44:18 +0000[diff] [blame]33 <li><a href="#multiclass">Multiclass definitions and instances</a></li>
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]34 </ol></li>
35 <li><a href="#filescope">File scope entities</a>
Chris Lattnerb54c99c2004-02-06 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 Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]39 </ol></li>
40 </ol></li>
41 <li><a href="#backends">TableGen backends</a>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]42 <ol>
Chris Lattnerfa6f3092004-02-06 06:04:25 +0000[diff] [blame]43 <li><a href="#">todo</a></li>
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]44 </ol></li>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]45</ul>
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]46</div>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]47
Chris Lattner7911ce22004-05-23 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 Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]52<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]53<h2><a name="introduction">Introduction</a></h2>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]54<!-- *********************************************************************** -->
55
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]56<div>
Chris Lattnerb54c99c2004-02-06 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 Lattner1aab3272004-07-26 21:16:55 +0000[diff] [blame]68of TableGen is the <a href="CodeGenerator.html">LLVM code generator</a>.</p>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]69
Misha Brukman85234ac2004-05-12 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 Wendling643eb5d2008-02-12 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 Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]73distribution, respectively.</p>
Chris Lattnerfa6f3092004-02-06 06:04:25 +0000[diff] [blame]74
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]75<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]76<h3><a name="concepts">Basic concepts</a></h3>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]77
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]78<div>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]79
Misha Brukman85234ac2004-05-12 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 Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]82
Misha Brukman85234ac2004-05-12 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 Wendling643eb5d2008-02-12 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 Lattnerb54c99c2004-02-06 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 Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]88taken care of and are fixed by TableGen.</p>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]89
Misha Brukman85234ac2004-05-12 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 Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]93
Misha Brukman85234ac2004-05-12 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 Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]96abstractions for either the domain they are targeting (such as "Register",
Misha Brukman85234ac2004-05-12 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 Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]103
Chris Lattner84b35982006-09-01 21:44:18 +0000[diff] [blame]104<p><b>TableGen multiclasses</b> are groups of abstract records that are
David Greenede444af2009-04-22 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 Lattner84b35982006-09-01 21:44:18 +0000[diff] [blame]109
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]110</div>
111
112<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]113<h3><a name="example">An example record</a></h3>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]114
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]115<div>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]116
Misha Brukman85234ac2004-05-12 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 Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]121
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]122<div class="doc_code">
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]123<pre>
124...
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]125<b>def</b> ADD32rr { <i>// Instruction X86Inst I</i>
Chris Lattnerfa6f3092004-02-06 06:04:25 +0000[diff] [blame]126 <b>string</b> Namespace = "X86";
Bill Wendling643eb5d2008-02-12 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 Lattnerfa6f3092004-02-06 06:04:25 +0000[diff] [blame]131 <b>list</b>&lt;Register&gt; Uses = [];
Bill Wendling643eb5d2008-02-12 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 Lattnerfa6f3092004-02-06 06:04:25 +0000[diff] [blame]136 <b>bit</b> isReturn = 0;
137 <b>bit</b> isBranch = 0;
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]138 <b>bit</b> isIndirectBranch = 0;
139 <b>bit</b> isBarrier = 0;
Chris Lattnerfa6f3092004-02-06 06:04:25 +0000[diff] [blame]140 <b>bit</b> isCall = 0;
Dan Gohman15511cf2008-12-03 18:15:48 +0000[diff] [blame]141 <b>bit</b> canFoldAsLoad = 0;
Bill Wendling643eb5d2008-02-12 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 Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]145 <b>bit</b> isConvertibleToThreeAddress = 1;
146 <b>bit</b> isCommutable = 1;
Chris Lattnerfa6f3092004-02-06 06:04:25 +0000[diff] [blame]147 <b>bit</b> isTerminator = 0;
Bill Wendling643eb5d2008-02-12 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 Gohman533297b2009-10-29 18:10:34 +0000[diff] [blame]151 <b>bit</b> usesCustomInserter = 0;
Bill Wendling643eb5d2008-02-12 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 Wendling643eb5d2008-02-12 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 Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]160 Format Form = MRMDestReg;
Bill Wendling643eb5d2008-02-12 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 Lattnerfa6f3092004-02-06 06:04:25 +0000[diff] [blame]164 <b>bit</b> hasOpSizePrefix = 0;
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]165 <b>bit</b> hasAdSizePrefix = 0;
Chris Lattnerfa6f3092004-02-06 06:04:25 +0000[diff] [blame]166 <b>bits</b>&lt;4&gt; Prefix = { 0, 0, 0, 0 };
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]167 <b>bit</b> hasREX_WPrefix = 0;
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]168 FPFormat FPForm = ?;
Chris Lattnerfa6f3092004-02-06 06:04:25 +0000[diff] [blame]169 <b>bits</b>&lt;3&gt; FPFormBits = { 0, 0, 0 };
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]170}
171...
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]172</pre>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]173</div>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]174
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]175<p>This definition corresponds to a 32-bit register-register add instruction in
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]176the X86. The string after the '<tt>def</tt>' string indicates the name of the
Bill Wendling643eb5d2008-02-12 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 Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]185
Misha Brukman85234ac2004-05-12 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 Gohman8ff4b432010-02-26 02:15:17 +0000[diff] [blame]188unmaintainable, prone to bugs, and tiring to do in the first place. Because we
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]189are using TableGen, all of the information was derived from the following
190definition:</p>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]191
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]192<div class="doc_code">
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]193<pre>
Bill Wendling643eb5d2008-02-12 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 Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]201</pre>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]202</div>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]203
Bill Wendling643eb5d2008-02-12 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 Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]209
David Greenedc5287c2011-10-19 13:04:56 +0000[diff] [blame]210<p>Each def record has a special entry called "NAME." This is the
211name of the def ("ADD32rr" above). In the general case def names can
212be formed from various kinds of string processing expressions and NAME
213resolves to the final value obtained after resolving all of those
214expressions. The user may refer to NAME anywhere she desires to use
215the ultimate name of the def. NAME should not be defined anywhere
216else in user code to avoid conflict problems.</p>
217
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]218</div>
219
220<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]221<h3><a name="running">Running TableGen</a></h3>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]222
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]223<div>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]224
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]225<p>TableGen runs just like any other LLVM tool. The first (optional) argument
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]226specifies the file to read. If a filename is not specified, <tt>tblgen</tt>
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]227reads from standard input.</p>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]228
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]229<p>To be useful, one of the <a href="#backends">TableGen backends</a> must be
230used. These backends are selectable on the command line (type '<tt>tblgen
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]231-help</tt>' for a list). For example, to get a list of all of the definitions
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]232that subclass a particular type (which can be useful for building up an enum
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]233list of these records), use the <tt>-print-enums</tt> option:</p>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]234
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]235<div class="doc_code">
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]236<pre>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]237$ tblgen X86.td -print-enums -class=Register
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]238AH, AL, AX, BH, BL, BP, BPL, BX, CH, CL, CX, DH, DI, DIL, DL, DX, EAX, EBP, EBX,
239ECX, EDI, EDX, EFLAGS, EIP, ESI, ESP, FP0, FP1, FP2, FP3, FP4, FP5, FP6, IP,
240MM0, MM1, MM2, MM3, MM4, MM5, MM6, MM7, R10, R10B, R10D, R10W, R11, R11B, R11D,
241R11W, R12, R12B, R12D, R12W, R13, R13B, R13D, R13W, R14, R14B, R14D, R14W, R15,
242R15B, R15D, R15W, R8, R8B, R8D, R8W, R9, R9B, R9D, R9W, RAX, RBP, RBX, RCX, RDI,
243RDX, RIP, RSI, RSP, SI, SIL, SP, SPL, ST0, ST1, ST2, ST3, ST4, ST5, ST6, ST7,
244XMM0, XMM1, XMM10, XMM11, XMM12, XMM13, XMM14, XMM15, XMM2, XMM3, XMM4, XMM5,
245XMM6, XMM7, XMM8, XMM9,
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]246
247$ tblgen X86.td -print-enums -class=Instruction
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]248ABS_F, ABS_Fp32, ABS_Fp64, ABS_Fp80, ADC32mi, ADC32mi8, ADC32mr, ADC32ri,
249ADC32ri8, ADC32rm, ADC32rr, ADC64mi32, ADC64mi8, ADC64mr, ADC64ri32, ADC64ri8,
250ADC64rm, ADC64rr, ADD16mi, ADD16mi8, ADD16mr, ADD16ri, ADD16ri8, ADD16rm,
251ADD16rr, ADD32mi, ADD32mi8, ADD32mr, ADD32ri, ADD32ri8, ADD32rm, ADD32rr,
252ADD64mi32, ADD64mi8, ADD64mr, ADD64ri32, ...
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]253</pre>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]254</div>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]255
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]256<p>The default backend prints out all of the records, as described <a
257href="#example">above</a>.</p>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]258
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]259<p>If you plan to use TableGen, you will most likely have to <a
260href="#backends">write a backend</a> that extracts the information specific to
261what you need and formats it in the appropriate way.</p>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]262
263</div>
264
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]265</div>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]266
267<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]268<h2><a name="syntax">TableGen syntax</a></h2>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]269<!-- *********************************************************************** -->
270
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]271<div>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]272
273<p>TableGen doesn't care about the meaning of data (that is up to the backend to
274define), but it does care about syntax, and it enforces a simple type system.
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]275This section describes the syntax and the constructs allowed in a TableGen file.
276</p>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]277
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]278<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]279<h3><a name="primitives">TableGen primitives</a></h3>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]280
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]281<div>
282
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]283<!-- -------------------------------------------------------------------------->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]284<h4><a name="comments">TableGen comments</a></h4>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]285
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]286<div>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]287
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]288<p>TableGen supports BCPL style "<tt>//</tt>" comments, which run to the end of
289the line, and it also supports <b>nestable</b> "<tt>/* */</tt>" comments.</p>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]290
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]291</div>
292
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]293<!-- -------------------------------------------------------------------------->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]294<h4>
Misha Brukman78b648c2004-06-03 16:59:59 +0000[diff] [blame]295 <a name="types">The TableGen type system</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]296</h4>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]297
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]298<div>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]299
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]300<p>TableGen files are strongly typed, in a simple (but complete) type-system.
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]301These types are used to perform automatic conversions, check for errors, and to
302help interface designers constrain the input that they allow. Every <a
303href="#valuedef">value definition</a> is required to have an associated type.
304</p>
305
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]306<p>TableGen supports a mixture of very low-level types (such as <tt>bit</tt>)
307and very high-level types (such as <tt>dag</tt>). This flexibility is what
308allows it to describe a wide range of information conveniently and compactly.
309The TableGen types are:</p>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]310
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]311<dl>
Bill Wendling58d96d62008-02-12 07:09:05 +0000[diff] [blame]312<dt><tt><b>bit</b></tt></dt>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]313 <dd>A 'bit' is a boolean value that can hold either 0 or 1.</dd>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]314
Bill Wendling58d96d62008-02-12 07:09:05 +0000[diff] [blame]315<dt><tt><b>int</b></tt></dt>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]316 <dd>The 'int' type represents a simple 32-bit integer value, such as 5.</dd>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]317
Bill Wendling58d96d62008-02-12 07:09:05 +0000[diff] [blame]318<dt><tt><b>string</b></tt></dt>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]319 <dd>The 'string' type represents an ordered sequence of characters of
320 arbitrary length.</dd>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]321
Bill Wendling58d96d62008-02-12 07:09:05 +0000[diff] [blame]322<dt><tt><b>bits</b>&lt;n&gt;</tt></dt>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]323 <dd>A 'bits' type is an arbitrary, but fixed, size integer that is broken up
324 into individual bits. This type is useful because it can handle some bits
325 being defined while others are undefined.</dd>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]326
Bill Wendling58d96d62008-02-12 07:09:05 +0000[diff] [blame]327<dt><tt><b>list</b>&lt;ty&gt;</tt></dt>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]328 <dd>This type represents a list whose elements are some other type. The
329 contained type is arbitrary: it can even be another list type.</dd>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]330
Bill Wendling58d96d62008-02-12 07:09:05 +0000[diff] [blame]331<dt>Class type</dt>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]332 <dd>Specifying a class name in a type context means that the defined value
333 must be a subclass of the specified class. This is useful in conjunction with
334 the <b><tt>list</tt></b> type, for example, to constrain the elements of the
335 list to a common base class (e.g., a <tt><b>list</b>&lt;Register&gt;</tt> can
336 only contain definitions derived from the "<tt>Register</tt>" class).</dd>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]337
Bill Wendling58d96d62008-02-12 07:09:05 +0000[diff] [blame]338<dt><tt><b>dag</b></tt></dt>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]339 <dd>This type represents a nestable directed graph of elements.</dd>
340
Bill Wendling58d96d62008-02-12 07:09:05 +0000[diff] [blame]341<dt><tt><b>code</b></tt></dt>
Chris Lattnerca73cea2010-04-22 16:45:27 +0000[diff] [blame]342 <dd>This represents a big hunk of text. This is lexically distinct from
343 string values because it doesn't require escapeing double quotes and other
344 common characters that occur in code.</dd>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]345</dl>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]346
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]347<p>To date, these types have been sufficient for describing things that
348TableGen has been used for, but it is straight-forward to extend this list if
349needed.</p>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]350
351</div>
352
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]353<!-- -------------------------------------------------------------------------->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]354<h4>
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]355 <a name="values">TableGen values and expressions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]356</h4>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]357
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]358<div>
Misha Brukman78b648c2004-06-03 16:59:59 +0000[diff] [blame]359
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]360<p>TableGen allows for a pretty reasonable number of different expression forms
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]361when building up values. These forms allow the TableGen file to be written in a
362natural syntax and flavor for the application. The current expression forms
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]363supported include:</p>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]364
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]365<dl>
Bill Wendling58d96d62008-02-12 07:09:05 +0000[diff] [blame]366<dt><tt>?</tt></dt>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]367 <dd>uninitialized field</dd>
Bill Wendling58d96d62008-02-12 07:09:05 +0000[diff] [blame]368<dt><tt>0b1001011</tt></dt>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]369 <dd>binary integer value</dd>
Bill Wendling58d96d62008-02-12 07:09:05 +0000[diff] [blame]370<dt><tt>07654321</tt></dt>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]371 <dd>octal integer value (indicated by a leading 0)</dd>
Bill Wendling58d96d62008-02-12 07:09:05 +0000[diff] [blame]372<dt><tt>7</tt></dt>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]373 <dd>decimal integer value</dd>
Bill Wendling58d96d62008-02-12 07:09:05 +0000[diff] [blame]374<dt><tt>0x7F</tt></dt>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]375 <dd>hexadecimal integer value</dd>
Bill Wendling58d96d62008-02-12 07:09:05 +0000[diff] [blame]376<dt><tt>"foo"</tt></dt>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]377 <dd>string value</dd>
Bill Wendling58d96d62008-02-12 07:09:05 +0000[diff] [blame]378<dt><tt>[{ ... }]</tt></dt>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]379 <dd>code fragment</dd>
Benjamin Kramere15192b2009-08-05 15:42:44 +0000[diff] [blame]380<dt><tt>[ X, Y, Z ]&lt;type&gt;</tt></dt>
381 <dd>list value. &lt;type&gt; is the type of the list
David Greeneccbfb8d2009-06-08 22:38:07 +0000[diff] [blame]382element and is usually optional. In rare cases,
383TableGen is unable to deduce the element type in
384which case the user must specify it explicitly.</dd>
Bill Wendling58d96d62008-02-12 07:09:05 +0000[diff] [blame]385<dt><tt>{ a, b, c }</tt></dt>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]386 <dd>initializer for a "bits&lt;3&gt;" value</dd>
Bill Wendling58d96d62008-02-12 07:09:05 +0000[diff] [blame]387<dt><tt>value</tt></dt>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]388 <dd>value reference</dd>
Bill Wendling58d96d62008-02-12 07:09:05 +0000[diff] [blame]389<dt><tt>value{17}</tt></dt>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]390 <dd>access to one bit of a value</dd>
Bill Wendling58d96d62008-02-12 07:09:05 +0000[diff] [blame]391<dt><tt>value{15-17}</tt></dt>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]392 <dd>access to multiple bits of a value</dd>
Bill Wendling58d96d62008-02-12 07:09:05 +0000[diff] [blame]393<dt><tt>DEF</tt></dt>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]394 <dd>reference to a record definition</dd>
Bill Wendling58d96d62008-02-12 07:09:05 +0000[diff] [blame]395<dt><tt>CLASS&lt;val list&gt;</tt></dt>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]396 <dd>reference to a new anonymous definition of CLASS with the specified
397 template arguments.</dd>
Bill Wendling58d96d62008-02-12 07:09:05 +0000[diff] [blame]398<dt><tt>X.Y</tt></dt>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]399 <dd>reference to the subfield of a value</dd>
Bill Wendling58d96d62008-02-12 07:09:05 +0000[diff] [blame]400<dt><tt>list[4-7,17,2-3]</tt></dt>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]401 <dd>A slice of the 'list' list, including elements 4,5,6,7,17,2, and 3 from
402 it. Elements may be included multiple times.</dd>
Bill Wendling58d96d62008-02-12 07:09:05 +0000[diff] [blame]403<dt><tt>(DEF a, b)</tt></dt>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]404 <dd>a dag value. The first element is required to be a record definition, the
405 remaining elements in the list may be arbitrary other values, including nested
406 `<tt>dag</tt>' values.</dd>
Bill Wendling58d96d62008-02-12 07:09:05 +0000[diff] [blame]407<dt><tt>!strconcat(a, b)</tt></dt>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]408 <dd>A string value that is the result of concatenating the 'a' and 'b'
409 strings.</dd>
David Greene40230c42011-10-19 13:04:59 +0000[diff] [blame^]410<dt><tt>str1#str2</tt></dt>
411 <dd>"#" (paste) is a shorthand for !strconcat. It may concatenate
412 things that are not quoted strings, in which case an implicit
413 !cast<string> is done on the operand of the paste.</dd>
Benjamin Kramere15192b2009-08-05 15:42:44 +0000[diff] [blame]414<dt><tt>!cast&lt;type&gt;(a)</tt></dt>
David Greenee6c27de2009-05-14 21:22:49 +0000[diff] [blame]415 <dd>A symbol of type <em>type</em> obtained by looking up the string 'a' in
416the symbol table. If the type of 'a' does not match <em>type</em>, TableGen
Benjamin Kramere15192b2009-08-05 15:42:44 +0000[diff] [blame]417aborts with an error. !cast&lt;string&gt; is a special case in that the argument must
David Greene2c026622009-06-29 20:05:29 +0000[diff] [blame]418be an object defined by a 'def' construct.</dd>
David Greene4afc5092009-05-14 21:54:42 +0000[diff] [blame]419<dt><tt>!subst(a, b, c)</tt></dt>
420 <dd>If 'a' and 'b' are of string type or are symbol references, substitute
421'b' for 'a' in 'c.' This operation is analogous to $(subst) in GNU make.</dd>
David Greenebeb31a52009-05-14 22:23:47 +0000[diff] [blame]422<dt><tt>!foreach(a, b, c)</tt></dt>
423 <dd>For each member 'b' of dag or list 'a' apply operator 'c.' 'b' is a
424dummy variable that should be declared as a member variable of an instantiated
425class. This operation is analogous to $(foreach) in GNU make.</dd>
David Greene1434f662011-01-07 17:05:37 +0000[diff] [blame]426<dt><tt>!head(a)</tt></dt>
David Greene5f9f9ba2009-05-14 22:38:31 +0000[diff] [blame]427 <dd>The first element of list 'a.'</dd>
David Greene1434f662011-01-07 17:05:37 +0000[diff] [blame]428<dt><tt>!tail(a)</tt></dt>
David Greene5f9f9ba2009-05-14 22:38:31 +0000[diff] [blame]429 <dd>The 2nd-N elements of list 'a.'</dd>
David Greene1434f662011-01-07 17:05:37 +0000[diff] [blame]430<dt><tt>!empty(a)</tt></dt>
David Greene5f9f9ba2009-05-14 22:38:31 +0000[diff] [blame]431 <dd>An integer {0,1} indicating whether list 'a' is empty.</dd>
David Greene9bea7c82009-05-14 23:26:46 +0000[diff] [blame]432<dt><tt>!if(a,b,c)</tt></dt>
Bruno Cardoso Lopeseba8f182010-06-17 00:31:36 +0000[diff] [blame]433 <dd>'b' if the result of 'int' or 'bit' operator 'a' is nonzero,
434 'c' otherwise.</dd>
David Greene6786d5e2010-01-05 19:11:42 +0000[diff] [blame]435<dt><tt>!eq(a,b)</tt></dt>
Chris Lattner150d20e2010-10-31 19:22:57 +0000[diff] [blame]436 <dd>'bit 1' if string a is equal to string b, 0 otherwise. This
Benjamin Kramer943beeb2010-10-30 21:07:28 +0000[diff] [blame]437 only operates on string, int and bit objects. Use !cast&lt;string&gt; to
Bruno Cardoso Lopese87de412010-06-16 23:24:12 +0000[diff] [blame]438 compare other types of objects.</dd>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]439</dl>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]440
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]441<p>Note that all of the values have rules specifying how they convert to values
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]442for different types. These rules allow you to assign a value like "<tt>7</tt>"
443to a "<tt>bits&lt;4&gt;</tt>" value, for example.</p>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]444
445</div>
446
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]447</div>
448
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]449<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]450<h3>
Misha Brukman78b648c2004-06-03 16:59:59 +0000[diff] [blame]451 <a name="classesdefs">Classes and definitions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]452</h3>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]453
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]454<div>
Misha Brukman78b648c2004-06-03 16:59:59 +0000[diff] [blame]455
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]456<p>As mentioned in the <a href="#concepts">intro</a>, classes and definitions
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]457(collectively known as 'records') in TableGen are the main high-level unit of
458information that TableGen collects. Records are defined with a <tt>def</tt> or
459<tt>class</tt> keyword, the record name, and an optional list of "<a
Misha Brukman179bf4b2004-06-03 23:42:24 +0000[diff] [blame]460href="#templateargs">template arguments</a>". If the record has superclasses,
Jeff Cohen0b81cda2005-10-24 16:54:55 +0000[diff] [blame]461they are specified as a comma separated list that starts with a colon character
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]462("<tt>:</tt>"). If <a href="#valuedef">value definitions</a> or <a
463href="#recordlet">let expressions</a> are needed for the class, they are
464enclosed in curly braces ("<tt>{}</tt>"); otherwise, the record ends with a
465semicolon.</p>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]466
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]467<p>Here is a simple TableGen file:</p>
468
469<div class="doc_code">
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]470<pre>
Chris Lattnerfa6f3092004-02-06 06:04:25 +0000[diff] [blame]471<b>class</b> C { <b>bit</b> V = 1; }
472<b>def</b> X : C;
473<b>def</b> Y : C {
474 <b>string</b> Greeting = "hello";
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]475}
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]476</pre>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]477</div>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]478
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]479<p>This example defines two definitions, <tt>X</tt> and <tt>Y</tt>, both of
480which derive from the <tt>C</tt> class. Because of this, they both get the
481<tt>V</tt> bit value. The <tt>Y</tt> definition also gets the Greeting member
482as well.</p>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]483
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]484<p>In general, classes are useful for collecting together the commonality
485between a group of records and isolating it in a single place. Also, classes
486permit the specification of default values for their subclasses, allowing the
487subclasses to override them as they wish.</p>
Chris Lattner23f54fa2004-02-06 06:37:00 +0000[diff] [blame]488
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]489<!---------------------------------------------------------------------------->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]490<h4>
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]491 <a name="valuedef">Value definitions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]492</h4>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]493
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]494<div>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]495
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]496<p>Value definitions define named entries in records. A value must be defined
John Criswellaa55c8c2004-02-12 18:11:53 +0000[diff] [blame]497before it can be referred to as the operand for another value definition or
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]498before the value is reset with a <a href="#recordlet">let expression</a>. A
499value is defined by specifying a <a href="#types">TableGen type</a> and a name.
500If an initial value is available, it may be specified after the type with an
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]501equal sign. Value definitions require terminating semicolons.</p>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]502
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]503</div>
504
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]505<!-- -------------------------------------------------------------------------->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]506<h4>
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]507 <a name="recordlet">'let' expressions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]508</h4>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]509
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]510<div>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]511
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]512<p>A record-level let expression is used to change the value of a value
513definition in a record. This is primarily useful when a superclass defines a
514value that a derived class or definition wants to override. Let expressions
515consist of the '<tt>let</tt>' keyword followed by a value name, an equal sign
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]516("<tt>=</tt>"), and a new value. For example, a new class could be added to the
517example above, redefining the <tt>V</tt> field for all of its subclasses:</p>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]518
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]519<div class="doc_code">
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]520<pre>
Chris Lattnerfa6f3092004-02-06 06:04:25 +0000[diff] [blame]521<b>class</b> D : C { let V = 0; }
522<b>def</b> Z : D;
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]523</pre>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]524</div>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]525
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]526<p>In this case, the <tt>Z</tt> definition will have a zero value for its "V"
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]527value, despite the fact that it derives (indirectly) from the <tt>C</tt> class,
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]528because the <tt>D</tt> class overrode its value.</p>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]529
530</div>
531
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]532<!-- -------------------------------------------------------------------------->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]533<h4>
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]534 <a name="templateargs">Class template arguments</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]535</h4>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]536
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]537<div>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]538
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]539<p>TableGen permits the definition of parameterized classes as well as normal
Chris Lattner23f54fa2004-02-06 06:37:00 +0000[diff] [blame]540concrete classes. Parameterized TableGen classes specify a list of variable
541bindings (which may optionally have defaults) that are bound when used. Here is
542a simple example:</p>
543
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]544<div class="doc_code">
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]545<pre>
Chris Lattner23f54fa2004-02-06 06:37:00 +0000[diff] [blame]546<b>class</b> FPFormat&lt;<b>bits</b>&lt;3&gt; val&gt; {
547 <b>bits</b>&lt;3&gt; Value = val;
548}
549<b>def</b> NotFP : FPFormat&lt;0&gt;;
550<b>def</b> ZeroArgFP : FPFormat&lt;1&gt;;
551<b>def</b> OneArgFP : FPFormat&lt;2&gt;;
552<b>def</b> OneArgFPRW : FPFormat&lt;3&gt;;
553<b>def</b> TwoArgFP : FPFormat&lt;4&gt;;
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]554<b>def</b> CompareFP : FPFormat&lt;5&gt;;
555<b>def</b> CondMovFP : FPFormat&lt;6&gt;;
556<b>def</b> SpecialFP : FPFormat&lt;7&gt;;
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]557</pre>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]558</div>
Chris Lattner23f54fa2004-02-06 06:37:00 +0000[diff] [blame]559
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]560<p>In this case, template arguments are used as a space efficient way to specify
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]561a list of "enumeration values", each with a "<tt>Value</tt>" field set to the
562specified integer.</p>
Chris Lattner23f54fa2004-02-06 06:37:00 +0000[diff] [blame]563
564<p>The more esoteric forms of <a href="#values">TableGen expressions</a> are
565useful in conjunction with template arguments. As an example:</p>
566
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]567<div class="doc_code">
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]568<pre>
Chris Lattner23f54fa2004-02-06 06:37:00 +0000[diff] [blame]569<b>class</b> ModRefVal&lt;<b>bits</b>&lt;2&gt; val&gt; {
570 <b>bits</b>&lt;2&gt; Value = val;
571}
572
573<b>def</b> None : ModRefVal&lt;0&gt;;
574<b>def</b> Mod : ModRefVal&lt;1&gt;;
575<b>def</b> Ref : ModRefVal&lt;2&gt;;
576<b>def</b> ModRef : ModRefVal&lt;3&gt;;
577
578<b>class</b> Value&lt;ModRefVal MR&gt; {
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]579 <i>// Decode some information into a more convenient format, while providing
Chris Lattner23f54fa2004-02-06 06:37:00 +0000[diff] [blame]580 // a nice interface to the user of the "Value" class.</i>
581 <b>bit</b> isMod = MR.Value{0};
582 <b>bit</b> isRef = MR.Value{1};
583
584 <i>// other stuff...</i>
585}
586
587<i>// Example uses</i>
588<b>def</b> bork : Value&lt;Mod&gt;;
589<b>def</b> zork : Value&lt;Ref&gt;;
590<b>def</b> hork : Value&lt;ModRef&gt;;
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]591</pre>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]592</div>
Chris Lattner23f54fa2004-02-06 06:37:00 +0000[diff] [blame]593
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]594<p>This is obviously a contrived example, but it shows how template arguments
595can be used to decouple the interface provided to the user of the class from the
Chris Lattner23f54fa2004-02-06 06:37:00 +0000[diff] [blame]596actual internal data representation expected by the class. In this case,
597running <tt>tblgen</tt> on the example prints the following definitions:</p>
598
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]599<div class="doc_code">
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]600<pre>
Chris Lattner23f54fa2004-02-06 06:37:00 +0000[diff] [blame]601<b>def</b> bork { <i>// Value</i>
Chris Lattner84b35982006-09-01 21:44:18 +0000[diff] [blame]602 <b>bit</b> isMod = 1;
603 <b>bit</b> isRef = 0;
Chris Lattner23f54fa2004-02-06 06:37:00 +0000[diff] [blame]604}
605<b>def</b> hork { <i>// Value</i>
Chris Lattner84b35982006-09-01 21:44:18 +0000[diff] [blame]606 <b>bit</b> isMod = 1;
607 <b>bit</b> isRef = 1;
Chris Lattner23f54fa2004-02-06 06:37:00 +0000[diff] [blame]608}
609<b>def</b> zork { <i>// Value</i>
Chris Lattner84b35982006-09-01 21:44:18 +0000[diff] [blame]610 <b>bit</b> isMod = 0;
611 <b>bit</b> isRef = 1;
Chris Lattner23f54fa2004-02-06 06:37:00 +0000[diff] [blame]612}
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]613</pre>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]614</div>
Chris Lattner23f54fa2004-02-06 06:37:00 +0000[diff] [blame]615
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]616<p> This shows that TableGen was able to dig into the argument and extract a
617piece of information that was requested by the designer of the "Value" class.
618For more realistic examples, please see existing users of TableGen, such as the
619X86 backend.</p>
Chris Lattner23f54fa2004-02-06 06:37:00 +0000[diff] [blame]620
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]621</div>
622
Chris Lattner84b35982006-09-01 21:44:18 +0000[diff] [blame]623<!-- -------------------------------------------------------------------------->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]624<h4>
Chris Lattner84b35982006-09-01 21:44:18 +0000[diff] [blame]625 <a name="multiclass">Multiclass definitions and instances</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]626</h4>
Chris Lattner84b35982006-09-01 21:44:18 +0000[diff] [blame]627
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]628<div>
Chris Lattner84b35982006-09-01 21:44:18 +0000[diff] [blame]629
630<p>
631While classes with template arguments are a good way to factor commonality
632between two instances of a definition, multiclasses allow a convenient notation
633for defining multiple definitions at once (instances of implicitly constructed
634classes). For example, consider an 3-address instruction set whose instructions
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]635come in two forms: "<tt>reg = reg op reg</tt>" and "<tt>reg = reg op imm</tt>"
636(e.g. SPARC). In this case, you'd like to specify in one place that this
637commonality exists, then in a separate place indicate what all the ops are.
Chris Lattner84b35982006-09-01 21:44:18 +0000[diff] [blame]638</p>
639
640<p>
641Here is an example TableGen fragment that shows this idea:
642</p>
643
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]644<div class="doc_code">
Chris Lattner84b35982006-09-01 21:44:18 +0000[diff] [blame]645<pre>
646<b>def</b> ops;
647<b>def</b> GPR;
648<b>def</b> Imm;
649<b>class</b> inst&lt;<b>int</b> opc, <b>string</b> asmstr, <b>dag</b> operandlist&gt;;
650
651<b>multiclass</b> ri_inst&lt;<b>int</b> opc, <b>string</b> asmstr&gt; {
652 def _rr : inst&lt;opc, !strconcat(asmstr, " $dst, $src1, $src2"),
653 (ops GPR:$dst, GPR:$src1, GPR:$src2)&gt;;
654 def _ri : inst&lt;opc, !strconcat(asmstr, " $dst, $src1, $src2"),
655 (ops GPR:$dst, GPR:$src1, Imm:$src2)&gt;;
656}
657
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]658<i>// Instantiations of the ri_inst multiclass.</i>
Chris Lattner84b35982006-09-01 21:44:18 +0000[diff] [blame]659<b>defm</b> ADD : ri_inst&lt;0b111, "add"&gt;;
660<b>defm</b> SUB : ri_inst&lt;0b101, "sub"&gt;;
661<b>defm</b> MUL : ri_inst&lt;0b100, "mul"&gt;;
662...
663</pre>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]664</div>
Chris Lattner84b35982006-09-01 21:44:18 +0000[diff] [blame]665
Chris Lattnere7173e12006-09-01 22:01:36 +0000[diff] [blame]666<p>The name of the resultant definitions has the multidef fragment names
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]667 appended to them, so this defines <tt>ADD_rr</tt>, <tt>ADD_ri</tt>,
David Greene56546132009-04-22 22:17:51 +0000[diff] [blame]668 <tt>SUB_rr</tt>, etc. A defm may inherit from multiple multiclasses,
669 instantiating definitions from each multiclass. Using a multiclass
670 this way is exactly equivalent to instantiating the classes multiple
671 times yourself, e.g. by writing:</p>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]672
673<div class="doc_code">
Chris Lattner84b35982006-09-01 21:44:18 +0000[diff] [blame]674<pre>
675<b>def</b> ops;
676<b>def</b> GPR;
677<b>def</b> Imm;
678<b>class</b> inst&lt;<b>int</b> opc, <b>string</b> asmstr, <b>dag</b> operandlist&gt;;
679
680<b>class</b> rrinst&lt;<b>int</b> opc, <b>string</b> asmstr&gt;
681 : inst&lt;opc, !strconcat(asmstr, " $dst, $src1, $src2"),
682 (ops GPR:$dst, GPR:$src1, GPR:$src2)&gt;;
683
684<b>class</b> riinst&lt;<b>int</b> opc, <b>string</b> asmstr&gt;
685 : inst&lt;opc, !strconcat(asmstr, " $dst, $src1, $src2"),
686 (ops GPR:$dst, GPR:$src1, Imm:$src2)&gt;;
687
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]688<i>// Instantiations of the ri_inst multiclass.</i>
Chris Lattner84b35982006-09-01 21:44:18 +0000[diff] [blame]689<b>def</b> ADD_rr : rrinst&lt;0b111, "add"&gt;;
690<b>def</b> ADD_ri : riinst&lt;0b111, "add"&gt;;
691<b>def</b> SUB_rr : rrinst&lt;0b101, "sub"&gt;;
692<b>def</b> SUB_ri : riinst&lt;0b101, "sub"&gt;;
693<b>def</b> MUL_rr : rrinst&lt;0b100, "mul"&gt;;
694<b>def</b> MUL_ri : riinst&lt;0b100, "mul"&gt;;
695...
696</pre>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]697</div>
Chris Lattner84b35982006-09-01 21:44:18 +0000[diff] [blame]698
Bruno Cardoso Lopes270562b2010-06-05 02:11:52 +0000[diff] [blame]699<p>
700A defm can also be used inside a multiclass providing several levels of
701multiclass instanciations.
702</p>
703
704<div class="doc_code">
705<pre>
706<b>class</b> Instruction&lt;bits&lt;4&gt; opc, string Name&gt; {
707 bits&lt;4&gt; opcode = opc;
708 string name = Name;
709}
710
711<b>multiclass</b> basic_r&lt;bits&lt;4&gt; opc&gt; {
712 <b>def</b> rr : Instruction&lt;opc, "rr"&gt;;
713 <b>def</b> rm : Instruction&lt;opc, "rm"&gt;;
714}
715
716<b>multiclass</b> basic_s&lt;bits&lt;4&gt; opc&gt; {
717 <b>defm</b> SS : basic_r&lt;opc&gt;;
718 <b>defm</b> SD : basic_r&lt;opc&gt;;
719 <b>def</b> X : Instruction&lt;opc, "x"&gt;;
720}
721
722<b>multiclass</b> basic_p&lt;bits&lt;4&gt; opc&gt; {
723 <b>defm</b> PS : basic_r&lt;opc&gt;;
724 <b>defm</b> PD : basic_r&lt;opc&gt;;
725 <b>def</b> Y : Instruction&lt;opc, "y"&gt;;
726}
727
728<b>defm</b> ADD : basic_s&lt;0xf&gt;, basic_p&lt;0xf&gt;;
729...
730
731<i>// Results</i>
732<b>def</b> ADDPDrm { ...
733<b>def</b> ADDPDrr { ...
734<b>def</b> ADDPSrm { ...
735<b>def</b> ADDPSrr { ...
736<b>def</b> ADDSDrm { ...
737<b>def</b> ADDSDrr { ...
738<b>def</b> ADDY { ...
739<b>def</b> ADDX { ...
740</pre>
741</div>
742
Bruno Cardoso Lopes6e0a99a2010-06-18 19:53:41 +0000[diff] [blame]743<p>
744defm declarations can inherit from classes too, the
745rule to follow is that the class list must start after the
746last multiclass, and there must be at least one multiclass
747before them.
748</p>
749
750<div class="doc_code">
751<pre>
752<b>class</b> XD { bits&lt;4&gt; Prefix = 11; }
753<b>class</b> XS { bits&lt;4&gt; Prefix = 12; }
754
755<b>class</b> I&lt;bits<4&gt; op> {
756 bits&lt;4&gt; opcode = op;
757}
758
759<b>multiclass</b> R {
760 <b>def</b> rr : I&lt;4&gt;;
761 <b>def</b> rm : I&lt;2&gt;;
762}
763
764<b>multiclass</b> Y {
765 <b>defm</b> SS : R, XD;
766 <b>defm</b> SD : R, XS;
767}
768
769<b>defm</b> Instr : Y;
770
771<i>// Results</i>
772<b>def</b> InstrSDrm {
773 bits&lt;4&gt; opcode = { 0, 0, 1, 0 };
774 bits&lt;4&gt; Prefix = { 1, 1, 0, 0 };
775}
776...
777<b>def</b> InstrSSrr {
778 bits&lt;4&gt; opcode = { 0, 1, 0, 0 };
779 bits&lt;4&gt; Prefix = { 1, 0, 1, 1 };
780}
781</pre>
782</div>
783
Chris Lattner84b35982006-09-01 21:44:18 +0000[diff] [blame]784</div>
785
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]786</div>
787
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]788<!-- ======================================================================= -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]789<h3>
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]790 <a name="filescope">File scope entities</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]791</h3>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]792
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]793<div>
794
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]795<!-- -------------------------------------------------------------------------->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]796<h4>
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]797 <a name="include">File inclusion</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]798</h4>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]799
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]800<div>
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]801<p>TableGen supports the '<tt>include</tt>' token, which textually substitutes
802the specified file in place of the include directive. The filename should be
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]803specified as a double quoted string immediately after the '<tt>include</tt>'
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]804keyword. Example:</p>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]805
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]806<div class="doc_code">
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]807<pre>
Chris Lattner23f54fa2004-02-06 06:37:00 +0000[diff] [blame]808<b>include</b> "foo.td"
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]809</pre>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]810</div>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]811
812</div>
813
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]814<!-- -------------------------------------------------------------------------->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]815<h4>
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]816 <a name="globallet">'let' expressions</a>
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]817</h4>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]818
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]819<div>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]820
821<p>"Let" expressions at file scope are similar to <a href="#recordlet">"let"
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]822expressions within a record</a>, except they can specify a value binding for
823multiple records at a time, and may be useful in certain other cases.
824File-scope let expressions are really just another way that TableGen allows the
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]825end-user to factor out commonality from the records.</p>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]826
Jeff Cohen0b81cda2005-10-24 16:54:55 +0000[diff] [blame]827<p>File-scope "let" expressions take a comma-separated list of bindings to
Matthijs Kooijman94199da2008-10-20 08:45:34 +0000[diff] [blame]828apply, and one or more records to bind the values in. Here are some
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]829examples:</p>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]830
Bill Wendling6171ab62010-12-08 02:46:25 +0000[diff] [blame]831<div class="doc_code">
832<pre>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]833<b>let</b> isTerminator = 1, isReturn = 1, isBarrier = 1, hasCtrlDep = 1 <b>in</b>
834 <b>def</b> RET : I&lt;0xC3, RawFrm, (outs), (ins), "ret", [(X86retflag 0)]&gt;;
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]835
Chris Lattnerfa6f3092004-02-06 06:04:25 +0000[diff] [blame]836<b>let</b> isCall = 1 <b>in</b>
837 <i>// All calls clobber the non-callee saved registers...</i>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]838 <b>let</b> Defs = [EAX, ECX, EDX, FP0, FP1, FP2, FP3, FP4, FP5, FP6, ST0,
839 MM0, MM1, MM2, MM3, MM4, MM5, MM6, MM7,
840 XMM0, XMM1, XMM2, XMM3, XMM4, XMM5, XMM6, XMM7, EFLAGS] <b>in</b> {
Dan Gohman364a39f2008-10-14 17:00:38 +0000[diff] [blame]841 <b>def</b> CALLpcrel32 : Ii32&lt;0xE8, RawFrm, (outs), (ins i32imm:$dst,variable_ops),
842 "call\t${dst:call}", []&gt;;
843 <b>def</b> CALL32r : I&lt;0xFF, MRM2r, (outs), (ins GR32:$dst, variable_ops),
844 "call\t{*}$dst", [(X86call GR32:$dst)]&gt;;
845 <b>def</b> CALL32m : I&lt;0xFF, MRM2m, (outs), (ins i32mem:$dst, variable_ops),
846 "call\t{*}$dst", []&gt;;
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]847 }
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]848</pre>
Bill Wendling6171ab62010-12-08 02:46:25 +0000[diff] [blame]849</div>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]850
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]851<p>File-scope "let" expressions are often useful when a couple of definitions
852need to be added to several records, and the records do not otherwise need to be
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]853opened, as in the case with the <tt>CALL*</tt> instructions above.</p>
854
Bruno Cardoso Lopesee65db32010-06-10 02:42:59 +0000[diff] [blame]855<p>It's also possible to use "let" expressions inside multiclasses, providing
856more ways to factor out commonality from the records, specially if using
857several levels of multiclass instanciations. This also avoids the need of using
858"let" expressions within subsequent records inside a multiclass.</p>
859
Benjamin Kramer943beeb2010-10-30 21:07:28 +0000[diff] [blame]860<pre class="doc_code">
Bruno Cardoso Lopesee65db32010-06-10 02:42:59 +0000[diff] [blame]861<b>multiclass </b>basic_r&lt;bits&lt;4&gt; opc&gt; {
862 <b>let </b>Predicates = [HasSSE2] in {
863 <b>def </b>rr : Instruction&lt;opc, "rr"&gt;;
864 <b>def </b>rm : Instruction&lt;opc, "rm"&gt;;
865 }
866 <b>let </b>Predicates = [HasSSE3] in
867 <b>def </b>rx : Instruction&lt;opc, "rx"&gt;;
868}
869
870<b>multiclass </b>basic_ss&lt;bits&lt;4&gt; opc&gt; {
871 <b>let </b>IsDouble = 0 in
872 <b>defm </b>SS : basic_r&lt;opc&gt;;
873
874 <b>let </b>IsDouble = 1 in
875 <b>defm </b>SD : basic_r&lt;opc&gt;;
876}
877
878<b>defm </b>ADD : basic_ss&lt;0xf&gt;;
879</pre>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]880</div>
881
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]882</div>
883
884</div>
885
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]886<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]887<h2><a name="codegen">Code Generator backend info</a></h2>
Evan Cheng11f911f2009-10-05 02:51:06 +0000[diff] [blame]888<!-- *********************************************************************** -->
889
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]890<div>
Benjamin Kramer943beeb2010-10-30 21:07:28 +0000[diff] [blame]891
Evan Cheng11f911f2009-10-05 02:51:06 +0000[diff] [blame]892<p>Expressions used by code generator to describe instructions and isel
893patterns:</p>
894
Benjamin Kramer943beeb2010-10-30 21:07:28 +0000[diff] [blame]895<dl>
Evan Cheng11f911f2009-10-05 02:51:06 +0000[diff] [blame]896<dt><tt>(implicit a)</tt></dt>
897 <dd>an implicitly defined physical register. This tells the dag instruction
898 selection emitter the input pattern's extra definitions matches implicit
899 physical register definitions.</dd>
Benjamin Kramer943beeb2010-10-30 21:07:28 +0000[diff] [blame]900</dl>
Evan Cheng11f911f2009-10-05 02:51:06 +0000[diff] [blame]901</div>
902
903<!-- *********************************************************************** -->
NAKAMURA Takumi05d02652011-04-18 23:59:50 +0000[diff] [blame]904<h2><a name="backends">TableGen backends</a></h2>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]905<!-- *********************************************************************** -->
906
NAKAMURA Takumif5af6ad2011-04-23 00:30:22 +0000[diff] [blame]907<div>
Bill Wendling643eb5d2008-02-12 07:06:19 +0000[diff] [blame]908
909<p>TODO: How they work, how to write one. This section should not contain
910details about any particular backend, except maybe -print-enums as an example.
911This should highlight the APIs in <tt>TableGen/Record.h</tt>.</p>
912
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]913</div>
914
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]915<!-- *********************************************************************** -->
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]916
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]917<hr>
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]918<address>
919 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
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Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]923
924 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumib9a33632011-04-09 02:13:37 +0000[diff] [blame]925 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
Chris Lattnerb54c99c2004-02-06 05:42:53 +0000[diff] [blame]926 Last modified: $Date$
Misha Brukman85234ac2004-05-12 18:31:21 +0000[diff] [blame]927</address>
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930</html>