1 //===--------------------- PredicateExpander.cpp --------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 /// \file
9 /// Functionalities used by the Tablegen backends to expand machine predicates.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "PredicateExpander.h"
14 #include "CodeGenSchedule.h" // Definition of STIPredicateFunction.
15 #include "llvm/TableGen/Record.h"
16 
17 namespace llvm {
18 
19 void PredicateExpander::expandTrue(raw_ostream &OS) { OS << "true"; }
20 void PredicateExpander::expandFalse(raw_ostream &OS) { OS << "false"; }
21 
22 void PredicateExpander::expandCheckImmOperand(raw_ostream &OS, int OpIndex,
23                                               int ImmVal,
24                                               StringRef FunctionMapper) {
25   if (!FunctionMapper.empty())
26     OS << FunctionMapper << "(";
27   OS << "MI" << (isByRef() ? "." : "->") << "getOperand(" << OpIndex
28      << ").getImm()";
29   if (!FunctionMapper.empty())
30     OS << ")";
31   OS << (shouldNegate() ? " != " : " == ") << ImmVal;
32 }
33 
34 void PredicateExpander::expandCheckImmOperand(raw_ostream &OS, int OpIndex,
35                                               StringRef ImmVal,
36                                               StringRef FunctionMapper) {
37   if (ImmVal.empty())
38     expandCheckImmOperandSimple(OS, OpIndex, FunctionMapper);
39 
40   if (!FunctionMapper.empty())
41     OS << FunctionMapper << "(";
42   OS << "MI" << (isByRef() ? "." : "->") << "getOperand(" << OpIndex
43      << ").getImm()";
44   if (!FunctionMapper.empty())
45     OS << ")";
46   OS << (shouldNegate() ? " != " : " == ") << ImmVal;
47 }
48 
49 void PredicateExpander::expandCheckImmOperandSimple(raw_ostream &OS,
50                                                     int OpIndex,
51                                                     StringRef FunctionMapper) {
52   if (shouldNegate())
53     OS << "!";
54   if (!FunctionMapper.empty())
55     OS << FunctionMapper << "(";
56   OS << "MI" << (isByRef() ? "." : "->") << "getOperand(" << OpIndex
57      << ").getImm()";
58   if (!FunctionMapper.empty())
59     OS << ")";
60 }
61 
62 void PredicateExpander::expandCheckRegOperand(raw_ostream &OS, int OpIndex,
63                                               const Record *Reg,
64                                               StringRef FunctionMapper) {
65   assert(Reg->isSubClassOf("Register") && "Expected a register Record!");
66 
67   if (!FunctionMapper.empty())
68     OS << FunctionMapper << "(";
69   OS << "MI" << (isByRef() ? "." : "->") << "getOperand(" << OpIndex
70      << ").getReg()";
71   if (!FunctionMapper.empty())
72     OS << ")";
73   OS << (shouldNegate() ? " != " : " == ");
74   const StringRef Str = Reg->getValueAsString("Namespace");
75   if (!Str.empty())
76     OS << Str << "::";
77   OS << Reg->getName();
78 }
79 
80 
81 void PredicateExpander::expandCheckRegOperandSimple(raw_ostream &OS,
82                                                     int OpIndex,
83                                                     StringRef FunctionMapper) {
84   if (shouldNegate())
85     OS << "!";
86   if (!FunctionMapper.empty())
87     OS << FunctionMapper << "(";
88   OS << "MI" << (isByRef() ? "." : "->") << "getOperand(" << OpIndex
89      << ").getReg()";
90   if (!FunctionMapper.empty())
91     OS << ")";
92 }
93 
94 void PredicateExpander::expandCheckInvalidRegOperand(raw_ostream &OS,
95                                                      int OpIndex) {
96   OS << "MI" << (isByRef() ? "." : "->") << "getOperand(" << OpIndex
97      << ").getReg() " << (shouldNegate() ? "!= " : "== ") << "0";
98 }
99 
100 void PredicateExpander::expandCheckSameRegOperand(raw_ostream &OS, int First,
101                                                   int Second) {
102   OS << "MI" << (isByRef() ? "." : "->") << "getOperand(" << First
103      << ").getReg() " << (shouldNegate() ? "!=" : "==") << " MI"
104      << (isByRef() ? "." : "->") << "getOperand(" << Second << ").getReg()";
105 }
106 
107 void PredicateExpander::expandCheckNumOperands(raw_ostream &OS, int NumOps) {
108   OS << "MI" << (isByRef() ? "." : "->") << "getNumOperands() "
109      << (shouldNegate() ? "!= " : "== ") << NumOps;
110 }
111 
112 void PredicateExpander::expandCheckOpcode(raw_ostream &OS, const Record *Inst) {
113   OS << "MI" << (isByRef() ? "." : "->") << "getOpcode() "
114      << (shouldNegate() ? "!= " : "== ") << Inst->getValueAsString("Namespace")
115      << "::" << Inst->getName();
116 }
117 
118 void PredicateExpander::expandCheckOpcode(raw_ostream &OS,
119                                           const RecVec &Opcodes) {
120   assert(!Opcodes.empty() && "Expected at least one opcode to check!");
121   bool First = true;
122 
123   if (Opcodes.size() == 1) {
124     OS << "( ";
125     expandCheckOpcode(OS, Opcodes[0]);
126     OS << " )";
127     return;
128   }
129 
130   OS << '(';
131   increaseIndentLevel();
132   for (const Record *Rec : Opcodes) {
133     OS << '\n';
134     OS.indent(getIndentLevel() * 2);
135     if (!First)
136       OS << (shouldNegate() ? "&& " : "|| ");
137 
138     expandCheckOpcode(OS, Rec);
139     First = false;
140   }
141 
142   OS << '\n';
143   decreaseIndentLevel();
144   OS.indent(getIndentLevel() * 2);
145   OS << ')';
146 }
147 
148 void PredicateExpander::expandCheckPseudo(raw_ostream &OS,
149                                           const RecVec &Opcodes) {
150   if (shouldExpandForMC())
151     expandFalse(OS);
152   else
153     expandCheckOpcode(OS, Opcodes);
154 }
155 
156 void PredicateExpander::expandPredicateSequence(raw_ostream &OS,
157                                                 const RecVec &Sequence,
158                                                 bool IsCheckAll) {
159   assert(!Sequence.empty() && "Found an invalid empty predicate set!");
160   if (Sequence.size() == 1)
161     return expandPredicate(OS, Sequence[0]);
162 
163   // Okay, there is more than one predicate in the set.
164   bool First = true;
165   OS << (shouldNegate() ? "!(" : "(");
166   increaseIndentLevel();
167 
168   bool OldValue = shouldNegate();
169   setNegatePredicate(false);
170   for (const Record *Rec : Sequence) {
171     OS << '\n';
172     OS.indent(getIndentLevel() * 2);
173     if (!First)
174       OS << (IsCheckAll ? "&& " : "|| ");
175     expandPredicate(OS, Rec);
176     First = false;
177   }
178   OS << '\n';
179   decreaseIndentLevel();
180   OS.indent(getIndentLevel() * 2);
181   OS << ')';
182   setNegatePredicate(OldValue);
183 }
184 
185 void PredicateExpander::expandTIIFunctionCall(raw_ostream &OS,
186                                               StringRef MethodName) {
187   OS << (shouldNegate() ? "!" : "");
188   OS << TargetName << (shouldExpandForMC() ? "_MC::" : "InstrInfo::");
189   OS << MethodName << (isByRef() ? "(MI)" : "(*MI)");
190 }
191 
192 void PredicateExpander::expandCheckIsRegOperand(raw_ostream &OS, int OpIndex) {
193   OS << (shouldNegate() ? "!" : "") << "MI" << (isByRef() ? "." : "->")
194      << "getOperand(" << OpIndex << ").isReg() ";
195 }
196 
197 void PredicateExpander::expandCheckIsImmOperand(raw_ostream &OS, int OpIndex) {
198   OS << (shouldNegate() ? "!" : "") << "MI" << (isByRef() ? "." : "->")
199      << "getOperand(" << OpIndex << ").isImm() ";
200 }
201 
202 void PredicateExpander::expandCheckFunctionPredicateWithTII(
203     raw_ostream &OS, StringRef MCInstFn, StringRef MachineInstrFn,
204     StringRef TIIPtr) {
205   if (!shouldExpandForMC()) {
206     OS << (TIIPtr.empty() ? "TII" : TIIPtr) << "->" << MachineInstrFn;
207     OS << (isByRef() ? "(MI)" : "(*MI)");
208     return;
209   }
210 
211   OS << MCInstFn << (isByRef() ? "(MI" : "(*MI") << ", MCII)";
212 }
213 
214 void PredicateExpander::expandCheckFunctionPredicate(raw_ostream &OS,
215                                                      StringRef MCInstFn,
216                                                      StringRef MachineInstrFn) {
217   OS << (shouldExpandForMC() ? MCInstFn : MachineInstrFn)
218      << (isByRef() ? "(MI)" : "(*MI)");
219 }
220 
221 void PredicateExpander::expandCheckNonPortable(raw_ostream &OS,
222                                                StringRef Code) {
223   if (shouldExpandForMC())
224     return expandFalse(OS);
225 
226   OS << '(' << Code << ')';
227 }
228 
229 void PredicateExpander::expandReturnStatement(raw_ostream &OS,
230                                               const Record *Rec) {
231   std::string Buffer;
232   raw_string_ostream SS(Buffer);
233 
234   SS << "return ";
235   expandPredicate(SS, Rec);
236   SS << ";";
237   OS << Buffer;
238 }
239 
240 void PredicateExpander::expandOpcodeSwitchCase(raw_ostream &OS,
241                                                const Record *Rec) {
242   const RecVec &Opcodes = Rec->getValueAsListOfDefs("Opcodes");
243   for (const Record *Opcode : Opcodes) {
244     OS.indent(getIndentLevel() * 2);
245     OS << "case " << Opcode->getValueAsString("Namespace")
246        << "::" << Opcode->getName() << ":\n";
247   }
248 
249   increaseIndentLevel();
250   OS.indent(getIndentLevel() * 2);
251   expandStatement(OS, Rec->getValueAsDef("CaseStmt"));
252   decreaseIndentLevel();
253 }
254 
255 void PredicateExpander::expandOpcodeSwitchStatement(raw_ostream &OS,
256                                                     const RecVec &Cases,
257                                                     const Record *Default) {
258   std::string Buffer;
259   raw_string_ostream SS(Buffer);
260 
261   SS << "switch(MI" << (isByRef() ? "." : "->") << "getOpcode()) {\n";
262   for (const Record *Rec : Cases) {
263     expandOpcodeSwitchCase(SS, Rec);
264     SS << '\n';
265   }
266 
267   // Expand the default case.
268   SS.indent(getIndentLevel() * 2);
269   SS << "default:\n";
270 
271   increaseIndentLevel();
272   SS.indent(getIndentLevel() * 2);
273   expandStatement(SS, Default);
274   decreaseIndentLevel();
275   SS << '\n';
276 
277   SS.indent(getIndentLevel() * 2);
278   SS << "} // end of switch-stmt";
279   OS << Buffer;
280 }
281 
282 void PredicateExpander::expandStatement(raw_ostream &OS, const Record *Rec) {
283   // Assume that padding has been added by the caller.
284   if (Rec->isSubClassOf("MCOpcodeSwitchStatement")) {
285     expandOpcodeSwitchStatement(OS, Rec->getValueAsListOfDefs("Cases"),
286                                 Rec->getValueAsDef("DefaultCase"));
287     return;
288   }
289 
290   if (Rec->isSubClassOf("MCReturnStatement")) {
291     expandReturnStatement(OS, Rec->getValueAsDef("Pred"));
292     return;
293   }
294 
295   llvm_unreachable("No known rules to expand this MCStatement");
296 }
297 
298 void PredicateExpander::expandPredicate(raw_ostream &OS, const Record *Rec) {
299   // Assume that padding has been added by the caller.
300   if (Rec->isSubClassOf("MCTrue")) {
301     if (shouldNegate())
302       return expandFalse(OS);
303     return expandTrue(OS);
304   }
305 
306   if (Rec->isSubClassOf("MCFalse")) {
307     if (shouldNegate())
308       return expandTrue(OS);
309     return expandFalse(OS);
310   }
311 
312   if (Rec->isSubClassOf("CheckNot")) {
313     flipNegatePredicate();
314     expandPredicate(OS, Rec->getValueAsDef("Pred"));
315     flipNegatePredicate();
316     return;
317   }
318 
319   if (Rec->isSubClassOf("CheckIsRegOperand"))
320     return expandCheckIsRegOperand(OS, Rec->getValueAsInt("OpIndex"));
321 
322   if (Rec->isSubClassOf("CheckIsImmOperand"))
323     return expandCheckIsImmOperand(OS, Rec->getValueAsInt("OpIndex"));
324 
325   if (Rec->isSubClassOf("CheckRegOperand"))
326     return expandCheckRegOperand(OS, Rec->getValueAsInt("OpIndex"),
327                                  Rec->getValueAsDef("Reg"),
328                                  Rec->getValueAsString("FunctionMapper"));
329 
330   if (Rec->isSubClassOf("CheckRegOperandSimple"))
331     return expandCheckRegOperandSimple(OS, Rec->getValueAsInt("OpIndex"),
332                                        Rec->getValueAsString("FunctionMapper"));
333 
334   if (Rec->isSubClassOf("CheckInvalidRegOperand"))
335     return expandCheckInvalidRegOperand(OS, Rec->getValueAsInt("OpIndex"));
336 
337   if (Rec->isSubClassOf("CheckImmOperand"))
338     return expandCheckImmOperand(OS, Rec->getValueAsInt("OpIndex"),
339                                  Rec->getValueAsInt("ImmVal"),
340                                  Rec->getValueAsString("FunctionMapper"));
341 
342   if (Rec->isSubClassOf("CheckImmOperand_s"))
343     return expandCheckImmOperand(OS, Rec->getValueAsInt("OpIndex"),
344                                  Rec->getValueAsString("ImmVal"),
345                                  Rec->getValueAsString("FunctionMapper"));
346 
347   if (Rec->isSubClassOf("CheckImmOperandSimple"))
348     return expandCheckImmOperandSimple(OS, Rec->getValueAsInt("OpIndex"),
349                                        Rec->getValueAsString("FunctionMapper"));
350 
351   if (Rec->isSubClassOf("CheckSameRegOperand"))
352     return expandCheckSameRegOperand(OS, Rec->getValueAsInt("FirstIndex"),
353                                      Rec->getValueAsInt("SecondIndex"));
354 
355   if (Rec->isSubClassOf("CheckNumOperands"))
356     return expandCheckNumOperands(OS, Rec->getValueAsInt("NumOps"));
357 
358   if (Rec->isSubClassOf("CheckPseudo"))
359     return expandCheckPseudo(OS, Rec->getValueAsListOfDefs("ValidOpcodes"));
360 
361   if (Rec->isSubClassOf("CheckOpcode"))
362     return expandCheckOpcode(OS, Rec->getValueAsListOfDefs("ValidOpcodes"));
363 
364   if (Rec->isSubClassOf("CheckAll"))
365     return expandPredicateSequence(OS, Rec->getValueAsListOfDefs("Predicates"),
366                                    /* AllOf */ true);
367 
368   if (Rec->isSubClassOf("CheckAny"))
369     return expandPredicateSequence(OS, Rec->getValueAsListOfDefs("Predicates"),
370                                    /* AllOf */ false);
371 
372   if (Rec->isSubClassOf("CheckFunctionPredicate")) {
373     return expandCheckFunctionPredicate(
374         OS, Rec->getValueAsString("MCInstFnName"),
375         Rec->getValueAsString("MachineInstrFnName"));
376   }
377 
378   if (Rec->isSubClassOf("CheckFunctionPredicateWithTII")) {
379     return expandCheckFunctionPredicateWithTII(
380         OS, Rec->getValueAsString("MCInstFnName"),
381         Rec->getValueAsString("MachineInstrFnName"),
382         Rec->getValueAsString("TIIPtrName"));
383   }
384 
385   if (Rec->isSubClassOf("CheckNonPortable"))
386     return expandCheckNonPortable(OS, Rec->getValueAsString("CodeBlock"));
387 
388   if (Rec->isSubClassOf("TIIPredicate"))
389     return expandTIIFunctionCall(OS, Rec->getValueAsString("FunctionName"));
390 
391   llvm_unreachable("No known rules to expand this MCInstPredicate");
392 }
393 
394 void STIPredicateExpander::expandHeader(raw_ostream &OS,
395                                         const STIPredicateFunction &Fn) {
396   const Record *Rec = Fn.getDeclaration();
397   StringRef FunctionName = Rec->getValueAsString("Name");
398 
399   OS.indent(getIndentLevel() * 2);
400   OS << "bool ";
401   if (shouldExpandDefinition())
402     OS << getClassPrefix() << "::";
403   OS << FunctionName << "(";
404   if (shouldExpandForMC())
405     OS << "const MCInst " << (isByRef() ? "&" : "*") << "MI";
406   else
407     OS << "const MachineInstr " << (isByRef() ? "&" : "*") << "MI";
408   if (Rec->getValueAsBit("UpdatesOpcodeMask"))
409     OS << ", APInt &Mask";
410   OS << (shouldExpandForMC() ? ", unsigned ProcessorID) const " : ") const ");
411   if (shouldExpandDefinition()) {
412     OS << "{\n";
413     return;
414   }
415 
416   if (Rec->getValueAsBit("OverridesBaseClassMember"))
417     OS << "override";
418   OS << ";\n";
419 }
420 
421 void STIPredicateExpander::expandPrologue(raw_ostream &OS,
422                                           const STIPredicateFunction &Fn) {
423   RecVec Delegates = Fn.getDeclaration()->getValueAsListOfDefs("Delegates");
424   bool UpdatesOpcodeMask =
425       Fn.getDeclaration()->getValueAsBit("UpdatesOpcodeMask");
426 
427   increaseIndentLevel();
428   unsigned IndentLevel = getIndentLevel();
429   for (const Record *Delegate : Delegates) {
430     OS.indent(IndentLevel * 2);
431     OS << "if (" << Delegate->getValueAsString("Name") << "(MI";
432     if (UpdatesOpcodeMask)
433       OS << ", Mask";
434     if (shouldExpandForMC())
435       OS << ", ProcessorID";
436     OS << "))\n";
437     OS.indent((1 + IndentLevel) * 2);
438     OS << "return true;\n\n";
439   }
440 
441   if (shouldExpandForMC())
442     return;
443 
444   OS.indent(IndentLevel * 2);
445   OS << "unsigned ProcessorID = getSchedModel().getProcessorID();\n";
446 }
447 
448 void STIPredicateExpander::expandOpcodeGroup(raw_ostream &OS, const OpcodeGroup &Group,
449                                              bool ShouldUpdateOpcodeMask) {
450   const OpcodeInfo &OI = Group.getOpcodeInfo();
451   for (const PredicateInfo &PI : OI.getPredicates()) {
452     const APInt &ProcModelMask = PI.ProcModelMask;
453     bool FirstProcID = true;
454     for (unsigned I = 0, E = ProcModelMask.getActiveBits(); I < E; ++I) {
455       if (!ProcModelMask[I])
456         continue;
457 
458       if (FirstProcID) {
459         OS.indent(getIndentLevel() * 2);
460         OS << "if (ProcessorID == " << I;
461       } else {
462         OS << " || ProcessorID == " << I;
463       }
464       FirstProcID = false;
465     }
466 
467     OS << ") {\n";
468 
469     increaseIndentLevel();
470     OS.indent(getIndentLevel() * 2);
471     if (ShouldUpdateOpcodeMask) {
472       if (PI.OperandMask.isZero())
473         OS << "Mask.clearAllBits();\n";
474       else
475         OS << "Mask = " << PI.OperandMask << ";\n";
476       OS.indent(getIndentLevel() * 2);
477     }
478     OS << "return ";
479     expandPredicate(OS, PI.Predicate);
480     OS << ";\n";
481     decreaseIndentLevel();
482     OS.indent(getIndentLevel() * 2);
483     OS << "}\n";
484   }
485 }
486 
487 void STIPredicateExpander::expandBody(raw_ostream &OS,
488                                       const STIPredicateFunction &Fn) {
489   bool UpdatesOpcodeMask =
490       Fn.getDeclaration()->getValueAsBit("UpdatesOpcodeMask");
491 
492   unsigned IndentLevel = getIndentLevel();
493   OS.indent(IndentLevel * 2);
494   OS << "switch(MI" << (isByRef() ? "." : "->") << "getOpcode()) {\n";
495   OS.indent(IndentLevel * 2);
496   OS << "default:\n";
497   OS.indent(IndentLevel * 2);
498   OS << "  break;";
499 
500   for (const OpcodeGroup &Group : Fn.getGroups()) {
501     for (const Record *Opcode : Group.getOpcodes()) {
502       OS << '\n';
503       OS.indent(IndentLevel * 2);
504       OS << "case " << getTargetName() << "::" << Opcode->getName() << ":";
505     }
506 
507     OS << '\n';
508     increaseIndentLevel();
509     expandOpcodeGroup(OS, Group, UpdatesOpcodeMask);
510 
511     OS.indent(getIndentLevel() * 2);
512     OS << "break;\n";
513     decreaseIndentLevel();
514   }
515 
516   OS.indent(IndentLevel * 2);
517   OS << "}\n";
518 }
519 
520 void STIPredicateExpander::expandEpilogue(raw_ostream &OS,
521                                           const STIPredicateFunction &Fn) {
522   OS << '\n';
523   OS.indent(getIndentLevel() * 2);
524   OS << "return ";
525   expandPredicate(OS, Fn.getDefaultReturnPredicate());
526   OS << ";\n";
527 
528   decreaseIndentLevel();
529   OS.indent(getIndentLevel() * 2);
530   StringRef FunctionName = Fn.getDeclaration()->getValueAsString("Name");
531   OS << "} // " << ClassPrefix << "::" << FunctionName << "\n\n";
532 }
533 
534 void STIPredicateExpander::expandSTIPredicate(raw_ostream &OS,
535                                               const STIPredicateFunction &Fn) {
536   const Record *Rec = Fn.getDeclaration();
537   if (shouldExpandForMC() && !Rec->getValueAsBit("ExpandForMC"))
538     return;
539 
540   expandHeader(OS, Fn);
541   if (shouldExpandDefinition()) {
542     expandPrologue(OS, Fn);
543     expandBody(OS, Fn);
544     expandEpilogue(OS, Fn);
545   }
546 }
547 
548 } // namespace llvm
549