aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/libs/llvm16/utils/TableGen/CodeGenSchedule.h
blob: bbf5381ad086b3f40072f2e673742b5b759ed477 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
//===- CodeGenSchedule.h - Scheduling Machine Models ------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file defines structures to encapsulate the machine model as described in
// the target description.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_UTILS_TABLEGEN_CODEGENSCHEDULE_H
#define LLVM_UTILS_TABLEGEN_CODEGENSCHEDULE_H

#include "llvm/ADT/APInt.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/TableGen/Record.h"
#include "llvm/TableGen/SetTheory.h"

namespace llvm {

class CodeGenTarget;
class CodeGenSchedModels;
class CodeGenInstruction;

using RecVec = std::vector<Record*>;
using RecIter = std::vector<Record*>::const_iterator;

using IdxVec = std::vector<unsigned>;
using IdxIter = std::vector<unsigned>::const_iterator;

/// We have two kinds of SchedReadWrites. Explicitly defined and inferred
/// sequences.  TheDef is nonnull for explicit SchedWrites, but Sequence may or
/// may not be empty. TheDef is null for inferred sequences, and Sequence must
/// be nonempty.
///
/// IsVariadic controls whether the variants are expanded into multiple operands
/// or a sequence of writes on one operand.
struct CodeGenSchedRW {
  unsigned Index;
  std::string Name;
  Record *TheDef;
  bool IsRead;
  bool IsAlias;
  bool HasVariants;
  bool IsVariadic;
  bool IsSequence;
  IdxVec Sequence;
  RecVec Aliases;

  CodeGenSchedRW()
    : Index(0), TheDef(nullptr), IsRead(false), IsAlias(false),
      HasVariants(false), IsVariadic(false), IsSequence(false) {}
  CodeGenSchedRW(unsigned Idx, Record *Def)
    : Index(Idx), TheDef(Def), IsAlias(false), IsVariadic(false) {
    Name = std::string(Def->getName());
    IsRead = Def->isSubClassOf("SchedRead");
    HasVariants = Def->isSubClassOf("SchedVariant");
    if (HasVariants)
      IsVariadic = Def->getValueAsBit("Variadic");

    // Read records don't currently have sequences, but it can be easily
    // added. Note that implicit Reads (from ReadVariant) may have a Sequence
    // (but no record).
    IsSequence = Def->isSubClassOf("WriteSequence");
  }

  CodeGenSchedRW(unsigned Idx, bool Read, ArrayRef<unsigned> Seq,
                 const std::string &Name)
      : Index(Idx), Name(Name), TheDef(nullptr), IsRead(Read), IsAlias(false),
        HasVariants(false), IsVariadic(false), IsSequence(true), Sequence(Seq) {
    assert(Sequence.size() > 1 && "implied sequence needs >1 RWs");
  }

  bool isValid() const {
    assert((!HasVariants || TheDef) && "Variant write needs record def");
    assert((!IsVariadic || HasVariants) && "Variadic write needs variants");
    assert((!IsSequence || !HasVariants) && "Sequence can't have variant");
    assert((!IsSequence || !Sequence.empty()) && "Sequence should be nonempty");
    assert((!IsAlias || Aliases.empty()) && "Alias cannot have aliases");
    return TheDef || !Sequence.empty();
  }

#ifndef NDEBUG
  void dump() const;
#endif
};

/// Represent a transition between SchedClasses induced by SchedVariant.
struct CodeGenSchedTransition {
  unsigned ToClassIdx;
  unsigned ProcIndex;
  RecVec PredTerm;
};

/// Scheduling class.
///
/// Each instruction description will be mapped to a scheduling class. There are
/// four types of classes:
///
/// 1) An explicitly defined itinerary class with ItinClassDef set.
/// Writes and ReadDefs are empty. ProcIndices contains 0 for any processor.
///
/// 2) An implied class with a list of SchedWrites and SchedReads that are
/// defined in an instruction definition and which are common across all
/// subtargets. ProcIndices contains 0 for any processor.
///
/// 3) An implied class with a list of InstRW records that map instructions to
/// SchedWrites and SchedReads per-processor. InstrClassMap should map the same
/// instructions to this class. ProcIndices contains all the processors that
/// provided InstrRW records for this class. ItinClassDef or Writes/Reads may
/// still be defined for processors with no InstRW entry.
///
/// 4) An inferred class represents a variant of another class that may be
/// resolved at runtime. ProcIndices contains the set of processors that may
/// require the class. ProcIndices are propagated through SchedClasses as
/// variants are expanded. Multiple SchedClasses may be inferred from an
/// itinerary class. Each inherits the processor index from the ItinRW record
/// that mapped the itinerary class to the variant Writes or Reads.
struct CodeGenSchedClass {
  unsigned Index;
  std::string Name;
  Record *ItinClassDef;

  IdxVec Writes;
  IdxVec Reads;
  // Sorted list of ProcIdx, where ProcIdx==0 implies any processor.
  IdxVec ProcIndices;

  std::vector<CodeGenSchedTransition> Transitions;

  // InstRW records associated with this class. These records may refer to an
  // Instruction no longer mapped to this class by InstrClassMap. These
  // Instructions should be ignored by this class because they have been split
  // off to join another inferred class.
  RecVec InstRWs;
  // InstRWs processor indices. Filled in inferFromInstRWs
  DenseSet<unsigned> InstRWProcIndices;

  CodeGenSchedClass(unsigned Index, std::string Name, Record *ItinClassDef)
    : Index(Index), Name(std::move(Name)), ItinClassDef(ItinClassDef) {}

  bool isKeyEqual(Record *IC, ArrayRef<unsigned> W,
                  ArrayRef<unsigned> R) const {
    return ItinClassDef == IC && ArrayRef(Writes) == W && ArrayRef(Reads) == R;
  }

  // Is this class generated from a variants if existing classes? Instructions
  // are never mapped directly to inferred scheduling classes.
  bool isInferred() const { return !ItinClassDef; }

#ifndef NDEBUG
  void dump(const CodeGenSchedModels *SchedModels) const;
#endif
};

/// Represent the cost of allocating a register of register class RCDef.
///
/// The cost of allocating a register is equivalent to the number of physical
/// registers used by the register renamer. Register costs are defined at
/// register class granularity.
struct CodeGenRegisterCost {
  Record *RCDef;
  unsigned Cost;
  bool AllowMoveElimination;
  CodeGenRegisterCost(Record *RC, unsigned RegisterCost, bool AllowMoveElim = false)
      : RCDef(RC), Cost(RegisterCost), AllowMoveElimination(AllowMoveElim) {}
  CodeGenRegisterCost(const CodeGenRegisterCost &) = default;
  CodeGenRegisterCost &operator=(const CodeGenRegisterCost &) = delete;
};

/// A processor register file.
///
/// This class describes a processor register file. Register file information is
/// currently consumed by external tools like llvm-mca to predict dispatch
/// stalls due to register pressure.
struct CodeGenRegisterFile {
  std::string Name;
  Record *RegisterFileDef;
  unsigned MaxMovesEliminatedPerCycle;
  bool AllowZeroMoveEliminationOnly;

  unsigned NumPhysRegs;
  std::vector<CodeGenRegisterCost> Costs;

  CodeGenRegisterFile(StringRef name, Record *def, unsigned MaxMoveElimPerCy = 0,
                      bool AllowZeroMoveElimOnly = false)
      : Name(name), RegisterFileDef(def),
        MaxMovesEliminatedPerCycle(MaxMoveElimPerCy),
        AllowZeroMoveEliminationOnly(AllowZeroMoveElimOnly),
        NumPhysRegs(0) {}

  bool hasDefaultCosts() const { return Costs.empty(); }
};

// Processor model.
//
// ModelName is a unique name used to name an instantiation of MCSchedModel.
//
// ModelDef is NULL for inferred Models. This happens when a processor defines
// an itinerary but no machine model. If the processor defines neither a machine
// model nor itinerary, then ModelDef remains pointing to NoModel. NoModel has
// the special "NoModel" field set to true.
//
// ItinsDef always points to a valid record definition, but may point to the
// default NoItineraries. NoItineraries has an empty list of InstrItinData
// records.
//
// ItinDefList orders this processor's InstrItinData records by SchedClass idx.
struct CodeGenProcModel {
  unsigned Index;
  std::string ModelName;
  Record *ModelDef;
  Record *ItinsDef;

  // Derived members...

  // Array of InstrItinData records indexed by a CodeGenSchedClass index.
  // This list is empty if the Processor has no value for Itineraries.
  // Initialized by collectProcItins().
  RecVec ItinDefList;

  // Map itinerary classes to per-operand resources.
  // This list is empty if no ItinRW refers to this Processor.
  RecVec ItinRWDefs;

  // List of unsupported feature.
  // This list is empty if the Processor has no UnsupportedFeatures.
  RecVec UnsupportedFeaturesDefs;

  // All read/write resources associated with this processor.
  RecVec WriteResDefs;
  RecVec ReadAdvanceDefs;

  // Per-operand machine model resources associated with this processor.
  RecVec ProcResourceDefs;

  // List of Register Files.
  std::vector<CodeGenRegisterFile> RegisterFiles;

  // Optional Retire Control Unit definition.
  Record *RetireControlUnit;

  // Load/Store queue descriptors.
  Record *LoadQueue;
  Record *StoreQueue;

  CodeGenProcModel(unsigned Idx, std::string Name, Record *MDef,
                   Record *IDef) :
    Index(Idx), ModelName(std::move(Name)), ModelDef(MDef), ItinsDef(IDef),
    RetireControlUnit(nullptr), LoadQueue(nullptr), StoreQueue(nullptr) {}

  bool hasItineraries() const {
    return !ItinsDef->getValueAsListOfDefs("IID").empty();
  }

  bool hasInstrSchedModel() const {
    return !WriteResDefs.empty() || !ItinRWDefs.empty();
  }

  bool hasExtraProcessorInfo() const {
    return RetireControlUnit || LoadQueue || StoreQueue ||
           !RegisterFiles.empty();
  }

  unsigned getProcResourceIdx(Record *PRDef) const;

  bool isUnsupported(const CodeGenInstruction &Inst) const;

#ifndef NDEBUG
  void dump() const;
#endif
};

/// Used to correlate instructions to MCInstPredicates specified by
/// InstructionEquivalentClass tablegen definitions.
///
/// Example: a XOR of a register with self, is a known zero-idiom for most
/// X86 processors.
///
/// Each processor can use a (potentially different) InstructionEquivalenceClass
///  definition to classify zero-idioms. That means, XORrr is likely to appear
/// in more than one equivalence class (where each class definition is
/// contributed by a different processor).
///
/// There is no guarantee that the same MCInstPredicate will be used to describe
/// equivalence classes that identify XORrr as a zero-idiom.
///
/// To be more specific, the requirements for being a zero-idiom XORrr may be
/// different for different processors.
///
/// Class PredicateInfo identifies a subset of processors that specify the same
/// requirements (i.e. same MCInstPredicate and OperandMask) for an instruction
/// opcode.
///
/// Back to the example. Field `ProcModelMask` will have one bit set for every
/// processor model that sees XORrr as a zero-idiom, and that specifies the same
/// set of constraints.
///
/// By construction, there can be multiple instances of PredicateInfo associated
/// with a same instruction opcode. For example, different processors may define
/// different constraints on the same opcode.
///
/// Field OperandMask can be used as an extra constraint.
/// It may be used to describe conditions that appy only to a subset of the
/// operands of a machine instruction, and the operands subset may not be the
/// same for all processor models.
struct PredicateInfo {
  llvm::APInt ProcModelMask; // A set of processor model indices.
  llvm::APInt OperandMask;   // An operand mask.
  const Record *Predicate;   // MCInstrPredicate definition.
  PredicateInfo(llvm::APInt CpuMask, llvm::APInt Operands, const Record *Pred)
      : ProcModelMask(CpuMask), OperandMask(Operands), Predicate(Pred) {}

  bool operator==(const PredicateInfo &Other) const {
    return ProcModelMask == Other.ProcModelMask &&
           OperandMask == Other.OperandMask && Predicate == Other.Predicate;
  }
};

/// A collection of PredicateInfo objects.
///
/// There is at least one OpcodeInfo object for every opcode specified by a
/// TIPredicate definition.
class OpcodeInfo {
  std::vector<PredicateInfo> Predicates;

  OpcodeInfo(const OpcodeInfo &Other) = delete;
  OpcodeInfo &operator=(const OpcodeInfo &Other) = delete;

public:
  OpcodeInfo() = default;
  OpcodeInfo &operator=(OpcodeInfo &&Other) = default;
  OpcodeInfo(OpcodeInfo &&Other) = default;

  ArrayRef<PredicateInfo> getPredicates() const { return Predicates; }

  void addPredicateForProcModel(const llvm::APInt &CpuMask,
                                const llvm::APInt &OperandMask,
                                const Record *Predicate);
};

/// Used to group together tablegen instruction definitions that are subject
/// to a same set of constraints (identified by an instance of OpcodeInfo).
class OpcodeGroup {
  OpcodeInfo Info;
  std::vector<const Record *> Opcodes;

  OpcodeGroup(const OpcodeGroup &Other) = delete;
  OpcodeGroup &operator=(const OpcodeGroup &Other) = delete;

public:
  OpcodeGroup(OpcodeInfo &&OpInfo) : Info(std::move(OpInfo)) {}
  OpcodeGroup(OpcodeGroup &&Other) = default;

  void addOpcode(const Record *Opcode) {
    assert(!llvm::is_contained(Opcodes, Opcode) && "Opcode already in set!");
    Opcodes.push_back(Opcode);
  }

  ArrayRef<const Record *> getOpcodes() const { return Opcodes; }
  const OpcodeInfo &getOpcodeInfo() const { return Info; }
};

/// An STIPredicateFunction descriptor used by tablegen backends to
/// auto-generate the body of a predicate function as a member of tablegen'd
/// class XXXGenSubtargetInfo.
class STIPredicateFunction {
  const Record *FunctionDeclaration;

  std::vector<const Record *> Definitions;
  std::vector<OpcodeGroup> Groups;

  STIPredicateFunction(const STIPredicateFunction &Other) = delete;
  STIPredicateFunction &operator=(const STIPredicateFunction &Other) = delete;

public:
  STIPredicateFunction(const Record *Rec) : FunctionDeclaration(Rec) {}
  STIPredicateFunction(STIPredicateFunction &&Other) = default;

  bool isCompatibleWith(const STIPredicateFunction &Other) const {
    return FunctionDeclaration == Other.FunctionDeclaration;
  }

  void addDefinition(const Record *Def) { Definitions.push_back(Def); }
  void addOpcode(const Record *OpcodeRec, OpcodeInfo &&Info) {
    if (Groups.empty() ||
        Groups.back().getOpcodeInfo().getPredicates() != Info.getPredicates())
      Groups.emplace_back(std::move(Info));
    Groups.back().addOpcode(OpcodeRec);
  }

  StringRef getName() const {
    return FunctionDeclaration->getValueAsString("Name");
  }
  const Record *getDefaultReturnPredicate() const {
    return FunctionDeclaration->getValueAsDef("DefaultReturnValue");
  }

  const Record *getDeclaration() const { return FunctionDeclaration; }
  ArrayRef<const Record *> getDefinitions() const { return Definitions; }
  ArrayRef<OpcodeGroup> getGroups() const { return Groups; }
};

using ProcModelMapTy = DenseMap<const Record *, unsigned>;

/// Top level container for machine model data.
class CodeGenSchedModels {
  RecordKeeper &Records;
  const CodeGenTarget &Target;

  // Map dag expressions to Instruction lists.
  SetTheory Sets;

  // List of unique processor models.
  std::vector<CodeGenProcModel> ProcModels;

  // Map Processor's MachineModel or ProcItin to a CodeGenProcModel index.
  ProcModelMapTy ProcModelMap;

  // Per-operand SchedReadWrite types.
  std::vector<CodeGenSchedRW> SchedWrites;
  std::vector<CodeGenSchedRW> SchedReads;

  // List of unique SchedClasses.
  std::vector<CodeGenSchedClass> SchedClasses;

  // Any inferred SchedClass has an index greater than NumInstrSchedClassses.
  unsigned NumInstrSchedClasses;

  RecVec ProcResourceDefs;
  RecVec ProcResGroups;

  // Map each instruction to its unique SchedClass index considering the
  // combination of it's itinerary class, SchedRW list, and InstRW records.
  using InstClassMapTy = DenseMap<Record*, unsigned>;
  InstClassMapTy InstrClassMap;

  std::vector<STIPredicateFunction> STIPredicates;
  std::vector<unsigned> getAllProcIndices() const;

public:
  CodeGenSchedModels(RecordKeeper& RK, const CodeGenTarget &TGT);

  // iterator access to the scheduling classes.
  using class_iterator = std::vector<CodeGenSchedClass>::iterator;
  using const_class_iterator = std::vector<CodeGenSchedClass>::const_iterator;
  class_iterator classes_begin() { return SchedClasses.begin(); }
  const_class_iterator classes_begin() const { return SchedClasses.begin(); }
  class_iterator classes_end() { return SchedClasses.end(); }
  const_class_iterator classes_end() const { return SchedClasses.end(); }
  iterator_range<class_iterator> classes() {
   return make_range(classes_begin(), classes_end());
  }
  iterator_range<const_class_iterator> classes() const {
   return make_range(classes_begin(), classes_end());
  }
  iterator_range<class_iterator> explicit_classes() {
    return make_range(classes_begin(), classes_begin() + NumInstrSchedClasses);
  }
  iterator_range<const_class_iterator> explicit_classes() const {
    return make_range(classes_begin(), classes_begin() + NumInstrSchedClasses);
  }

  Record *getModelOrItinDef(Record *ProcDef) const {
    Record *ModelDef = ProcDef->getValueAsDef("SchedModel");
    Record *ItinsDef = ProcDef->getValueAsDef("ProcItin");
    if (!ItinsDef->getValueAsListOfDefs("IID").empty()) {
      assert(ModelDef->getValueAsBit("NoModel")
             && "Itineraries must be defined within SchedMachineModel");
      return ItinsDef;
    }
    return ModelDef;
  }

  const CodeGenProcModel &getModelForProc(Record *ProcDef) const {
    Record *ModelDef = getModelOrItinDef(ProcDef);
    ProcModelMapTy::const_iterator I = ProcModelMap.find(ModelDef);
    assert(I != ProcModelMap.end() && "missing machine model");
    return ProcModels[I->second];
  }

  CodeGenProcModel &getProcModel(Record *ModelDef) {
    ProcModelMapTy::const_iterator I = ProcModelMap.find(ModelDef);
    assert(I != ProcModelMap.end() && "missing machine model");
    return ProcModels[I->second];
  }
  const CodeGenProcModel &getProcModel(Record *ModelDef) const {
    return const_cast<CodeGenSchedModels*>(this)->getProcModel(ModelDef);
  }

  // Iterate over the unique processor models.
  using ProcIter = std::vector<CodeGenProcModel>::const_iterator;
  ProcIter procModelBegin() const { return ProcModels.begin(); }
  ProcIter procModelEnd() const { return ProcModels.end(); }
  ArrayRef<CodeGenProcModel> procModels() const { return ProcModels; }

  // Return true if any processors have itineraries.
  bool hasItineraries() const;

  // Get a SchedWrite from its index.
  const CodeGenSchedRW &getSchedWrite(unsigned Idx) const {
    assert(Idx < SchedWrites.size() && "bad SchedWrite index");
    assert(SchedWrites[Idx].isValid() && "invalid SchedWrite");
    return SchedWrites[Idx];
  }
  // Get a SchedWrite from its index.
  const CodeGenSchedRW &getSchedRead(unsigned Idx) const {
    assert(Idx < SchedReads.size() && "bad SchedRead index");
    assert(SchedReads[Idx].isValid() && "invalid SchedRead");
    return SchedReads[Idx];
  }

  const CodeGenSchedRW &getSchedRW(unsigned Idx, bool IsRead) const {
    return IsRead ? getSchedRead(Idx) : getSchedWrite(Idx);
  }
  CodeGenSchedRW &getSchedRW(Record *Def) {
    bool IsRead = Def->isSubClassOf("SchedRead");
    unsigned Idx = getSchedRWIdx(Def, IsRead);
    return const_cast<CodeGenSchedRW&>(
      IsRead ? getSchedRead(Idx) : getSchedWrite(Idx));
  }
  const CodeGenSchedRW &getSchedRW(Record *Def) const {
    return const_cast<CodeGenSchedModels&>(*this).getSchedRW(Def);
  }

  unsigned getSchedRWIdx(const Record *Def, bool IsRead) const;

  // Return true if the given write record is referenced by a ReadAdvance.
  bool hasReadOfWrite(Record *WriteDef) const;

  // Get a SchedClass from its index.
  CodeGenSchedClass &getSchedClass(unsigned Idx) {
    assert(Idx < SchedClasses.size() && "bad SchedClass index");
    return SchedClasses[Idx];
  }
  const CodeGenSchedClass &getSchedClass(unsigned Idx) const {
    assert(Idx < SchedClasses.size() && "bad SchedClass index");
    return SchedClasses[Idx];
  }

  // Get the SchedClass index for an instruction. Instructions with no
  // itinerary, no SchedReadWrites, and no InstrReadWrites references return 0
  // for NoItinerary.
  unsigned getSchedClassIdx(const CodeGenInstruction &Inst) const;

  using SchedClassIter = std::vector<CodeGenSchedClass>::const_iterator;
  SchedClassIter schedClassBegin() const { return SchedClasses.begin(); }
  SchedClassIter schedClassEnd() const { return SchedClasses.end(); }
  ArrayRef<CodeGenSchedClass> schedClasses() const { return SchedClasses; }

  unsigned numInstrSchedClasses() const { return NumInstrSchedClasses; }

  void findRWs(const RecVec &RWDefs, IdxVec &Writes, IdxVec &Reads) const;
  void findRWs(const RecVec &RWDefs, IdxVec &RWs, bool IsRead) const;
  void expandRWSequence(unsigned RWIdx, IdxVec &RWSeq, bool IsRead) const;
  void expandRWSeqForProc(unsigned RWIdx, IdxVec &RWSeq, bool IsRead,
                          const CodeGenProcModel &ProcModel) const;

  unsigned addSchedClass(Record *ItinDef, ArrayRef<unsigned> OperWrites,
                         ArrayRef<unsigned> OperReads,
                         ArrayRef<unsigned> ProcIndices);

  unsigned findOrInsertRW(ArrayRef<unsigned> Seq, bool IsRead);

  Record *findProcResUnits(Record *ProcResKind, const CodeGenProcModel &PM,
                           ArrayRef<SMLoc> Loc) const;

  ArrayRef<STIPredicateFunction> getSTIPredicates() const {
    return STIPredicates;
  }
private:
  void collectProcModels();

  // Initialize a new processor model if it is unique.
  void addProcModel(Record *ProcDef);

  void collectSchedRW();

  std::string genRWName(ArrayRef<unsigned> Seq, bool IsRead);
  unsigned findRWForSequence(ArrayRef<unsigned> Seq, bool IsRead);

  void collectSchedClasses();

  void collectRetireControlUnits();

  void collectRegisterFiles();

  void collectOptionalProcessorInfo();

  std::string createSchedClassName(Record *ItinClassDef,
                                   ArrayRef<unsigned> OperWrites,
                                   ArrayRef<unsigned> OperReads);
  std::string createSchedClassName(const RecVec &InstDefs);
  void createInstRWClass(Record *InstRWDef);

  void collectProcItins();

  void collectProcItinRW();

  void collectProcUnsupportedFeatures();

  void inferSchedClasses();

  void checkMCInstPredicates() const;

  void checkSTIPredicates() const;

  void collectSTIPredicates();

  void collectLoadStoreQueueInfo();

  void checkCompleteness();

  void inferFromRW(ArrayRef<unsigned> OperWrites, ArrayRef<unsigned> OperReads,
                   unsigned FromClassIdx, ArrayRef<unsigned> ProcIndices);
  void inferFromItinClass(Record *ItinClassDef, unsigned FromClassIdx);
  void inferFromInstRWs(unsigned SCIdx);

  bool hasSuperGroup(RecVec &SubUnits, CodeGenProcModel &PM);
  void verifyProcResourceGroups(CodeGenProcModel &PM);

  void collectProcResources();

  void collectItinProcResources(Record *ItinClassDef);

  void collectRWResources(unsigned RWIdx, bool IsRead,
                          ArrayRef<unsigned> ProcIndices);

  void collectRWResources(ArrayRef<unsigned> Writes, ArrayRef<unsigned> Reads,
                          ArrayRef<unsigned> ProcIndices);

  void addProcResource(Record *ProcResourceKind, CodeGenProcModel &PM,
                       ArrayRef<SMLoc> Loc);

  void addWriteRes(Record *ProcWriteResDef, unsigned PIdx);

  void addReadAdvance(Record *ProcReadAdvanceDef, unsigned PIdx);
};

} // namespace llvm

#endif