1// Copyright 2014 the V8 project authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef V8_COMPILER_NODE_MATCHERS_H_
6#define V8_COMPILER_NODE_MATCHERS_H_
7
8#include <cmath>
9
10// TODO(turbofan): Move ExternalReference out of assembler.h
11#include "src/assembler.h"
12#include "src/base/compiler-specific.h"
13#include "src/compiler/node.h"
14#include "src/compiler/operator.h"
15#include "src/double.h"
16#include "src/globals.h"
17
18namespace v8 {
19namespace internal {
20namespace compiler {
21
22// A pattern matcher for nodes.
23struct NodeMatcher {
24  explicit NodeMatcher(Node* node) : node_(node) {}
25
26  Node* node() const { return node_; }
27  const Operator* op() const { return node()->op(); }
28  IrOpcode::Value opcode() const { return node()->opcode(); }
29
30  bool HasProperty(Operator::Property property) const {
31    return op()->HasProperty(property);
32  }
33  Node* InputAt(int index) const { return node()->InputAt(index); }
34
35  bool Equals(const Node* node) const { return node_ == node; }
36
37  bool IsComparison() const;
38
39#define DEFINE_IS_OPCODE(Opcode) \
40  bool Is##Opcode() const { return opcode() == IrOpcode::k##Opcode; }
41  ALL_OP_LIST(DEFINE_IS_OPCODE)
42#undef DEFINE_IS_OPCODE
43
44 private:
45  Node* node_;
46};
47
48
49// A pattern matcher for abitrary value constants.
50template <typename T, IrOpcode::Value kOpcode>
51struct ValueMatcher : public NodeMatcher {
52  typedef T ValueType;
53
54  explicit ValueMatcher(Node* node)
55      : NodeMatcher(node), value_(), has_value_(opcode() == kOpcode) {
56    if (has_value_) {
57      value_ = OpParameter<T>(node);
58    }
59  }
60
61  bool HasValue() const { return has_value_; }
62  const T& Value() const {
63    DCHECK(HasValue());
64    return value_;
65  }
66
67 private:
68  T value_;
69  bool has_value_;
70};
71
72
73template <>
74inline ValueMatcher<uint32_t, IrOpcode::kInt32Constant>::ValueMatcher(
75    Node* node)
76    : NodeMatcher(node),
77      value_(),
78      has_value_(opcode() == IrOpcode::kInt32Constant) {
79  if (has_value_) {
80    value_ = static_cast<uint32_t>(OpParameter<int32_t>(node));
81  }
82}
83
84
85template <>
86inline ValueMatcher<int64_t, IrOpcode::kInt64Constant>::ValueMatcher(Node* node)
87    : NodeMatcher(node), value_(), has_value_(false) {
88  if (opcode() == IrOpcode::kInt32Constant) {
89    value_ = OpParameter<int32_t>(node);
90    has_value_ = true;
91  } else if (opcode() == IrOpcode::kInt64Constant) {
92    value_ = OpParameter<int64_t>(node);
93    has_value_ = true;
94  }
95}
96
97
98template <>
99inline ValueMatcher<uint64_t, IrOpcode::kInt64Constant>::ValueMatcher(
100    Node* node)
101    : NodeMatcher(node), value_(), has_value_(false) {
102  if (opcode() == IrOpcode::kInt32Constant) {
103    value_ = static_cast<uint32_t>(OpParameter<int32_t>(node));
104    has_value_ = true;
105  } else if (opcode() == IrOpcode::kInt64Constant) {
106    value_ = static_cast<uint64_t>(OpParameter<int64_t>(node));
107    has_value_ = true;
108  }
109}
110
111
112// A pattern matcher for integer constants.
113template <typename T, IrOpcode::Value kOpcode>
114struct IntMatcher final : public ValueMatcher<T, kOpcode> {
115  explicit IntMatcher(Node* node) : ValueMatcher<T, kOpcode>(node) {}
116
117  bool Is(const T& value) const {
118    return this->HasValue() && this->Value() == value;
119  }
120  bool IsInRange(const T& low, const T& high) const {
121    return this->HasValue() && low <= this->Value() && this->Value() <= high;
122  }
123  bool IsMultipleOf(T n) const {
124    return this->HasValue() && (this->Value() % n) == 0;
125  }
126  bool IsPowerOf2() const {
127    return this->HasValue() && this->Value() > 0 &&
128           (this->Value() & (this->Value() - 1)) == 0;
129  }
130  bool IsNegativePowerOf2() const {
131    return this->HasValue() && this->Value() < 0 &&
132           (-this->Value() & (-this->Value() - 1)) == 0;
133  }
134  bool IsNegative() const { return this->HasValue() && this->Value() < 0; }
135};
136
137typedef IntMatcher<int32_t, IrOpcode::kInt32Constant> Int32Matcher;
138typedef IntMatcher<uint32_t, IrOpcode::kInt32Constant> Uint32Matcher;
139typedef IntMatcher<int64_t, IrOpcode::kInt64Constant> Int64Matcher;
140typedef IntMatcher<uint64_t, IrOpcode::kInt64Constant> Uint64Matcher;
141#if V8_HOST_ARCH_32_BIT
142typedef Int32Matcher IntPtrMatcher;
143typedef Uint32Matcher UintPtrMatcher;
144#else
145typedef Int64Matcher IntPtrMatcher;
146typedef Uint64Matcher UintPtrMatcher;
147#endif
148
149
150// A pattern matcher for floating point constants.
151template <typename T, IrOpcode::Value kOpcode>
152struct FloatMatcher final : public ValueMatcher<T, kOpcode> {
153  explicit FloatMatcher(Node* node) : ValueMatcher<T, kOpcode>(node) {}
154
155  bool Is(const T& value) const {
156    return this->HasValue() && this->Value() == value;
157  }
158  bool IsInRange(const T& low, const T& high) const {
159    return this->HasValue() && low <= this->Value() && this->Value() <= high;
160  }
161  bool IsMinusZero() const {
162    return this->Is(0.0) && std::signbit(this->Value());
163  }
164  bool IsNegative() const { return this->HasValue() && this->Value() < 0.0; }
165  bool IsNaN() const { return this->HasValue() && std::isnan(this->Value()); }
166  bool IsZero() const { return this->Is(0.0) && !std::signbit(this->Value()); }
167  bool IsNormal() const {
168    return this->HasValue() && std::isnormal(this->Value());
169  }
170  bool IsInteger() const {
171    return this->HasValue() && std::nearbyint(this->Value()) == this->Value();
172  }
173  bool IsPositiveOrNegativePowerOf2() const {
174    if (!this->HasValue() || (this->Value() == 0.0)) {
175      return false;
176    }
177    Double value = Double(this->Value());
178    return !value.IsInfinite() &&
179           base::bits::IsPowerOfTwo64(value.Significand());
180  }
181};
182
183typedef FloatMatcher<float, IrOpcode::kFloat32Constant> Float32Matcher;
184typedef FloatMatcher<double, IrOpcode::kFloat64Constant> Float64Matcher;
185typedef FloatMatcher<double, IrOpcode::kNumberConstant> NumberMatcher;
186
187
188// A pattern matcher for heap object constants.
189struct HeapObjectMatcher final
190    : public ValueMatcher<Handle<HeapObject>, IrOpcode::kHeapConstant> {
191  explicit HeapObjectMatcher(Node* node)
192      : ValueMatcher<Handle<HeapObject>, IrOpcode::kHeapConstant>(node) {}
193
194  bool Is(Handle<HeapObject> const& value) const {
195    return this->HasValue() && this->Value().address() == value.address();
196  }
197};
198
199
200// A pattern matcher for external reference constants.
201struct ExternalReferenceMatcher final
202    : public ValueMatcher<ExternalReference, IrOpcode::kExternalConstant> {
203  explicit ExternalReferenceMatcher(Node* node)
204      : ValueMatcher<ExternalReference, IrOpcode::kExternalConstant>(node) {}
205  bool Is(const ExternalReference& value) const {
206    return this->HasValue() && this->Value() == value;
207  }
208};
209
210
211// For shorter pattern matching code, this struct matches the inputs to
212// machine-level load operations.
213template <typename Object>
214struct LoadMatcher : public NodeMatcher {
215  explicit LoadMatcher(Node* node)
216      : NodeMatcher(node), object_(InputAt(0)), index_(InputAt(1)) {}
217
218  typedef Object ObjectMatcher;
219
220  Object const& object() const { return object_; }
221  IntPtrMatcher const& index() const { return index_; }
222
223 private:
224  Object const object_;
225  IntPtrMatcher const index_;
226};
227
228
229// For shorter pattern matching code, this struct matches both the left and
230// right hand sides of a binary operation and can put constants on the right
231// if they appear on the left hand side of a commutative operation.
232template <typename Left, typename Right>
233struct BinopMatcher : public NodeMatcher {
234  explicit BinopMatcher(Node* node)
235      : NodeMatcher(node), left_(InputAt(0)), right_(InputAt(1)) {
236    if (HasProperty(Operator::kCommutative)) PutConstantOnRight();
237  }
238  BinopMatcher(Node* node, bool allow_input_swap)
239      : NodeMatcher(node), left_(InputAt(0)), right_(InputAt(1)) {
240    if (allow_input_swap) PutConstantOnRight();
241  }
242
243  typedef Left LeftMatcher;
244  typedef Right RightMatcher;
245
246  const Left& left() const { return left_; }
247  const Right& right() const { return right_; }
248
249  bool IsFoldable() const { return left().HasValue() && right().HasValue(); }
250  bool LeftEqualsRight() const { return left().node() == right().node(); }
251
252 protected:
253  void SwapInputs() {
254    std::swap(left_, right_);
255    node()->ReplaceInput(0, left().node());
256    node()->ReplaceInput(1, right().node());
257  }
258
259 private:
260  void PutConstantOnRight() {
261    if (left().HasValue() && !right().HasValue()) {
262      SwapInputs();
263    }
264  }
265
266  Left left_;
267  Right right_;
268};
269
270typedef BinopMatcher<Int32Matcher, Int32Matcher> Int32BinopMatcher;
271typedef BinopMatcher<Uint32Matcher, Uint32Matcher> Uint32BinopMatcher;
272typedef BinopMatcher<Int64Matcher, Int64Matcher> Int64BinopMatcher;
273typedef BinopMatcher<Uint64Matcher, Uint64Matcher> Uint64BinopMatcher;
274typedef BinopMatcher<IntPtrMatcher, IntPtrMatcher> IntPtrBinopMatcher;
275typedef BinopMatcher<UintPtrMatcher, UintPtrMatcher> UintPtrBinopMatcher;
276typedef BinopMatcher<Float32Matcher, Float32Matcher> Float32BinopMatcher;
277typedef BinopMatcher<Float64Matcher, Float64Matcher> Float64BinopMatcher;
278typedef BinopMatcher<NumberMatcher, NumberMatcher> NumberBinopMatcher;
279typedef BinopMatcher<HeapObjectMatcher, HeapObjectMatcher>
280    HeapObjectBinopMatcher;
281
282template <class BinopMatcher, IrOpcode::Value kMulOpcode,
283          IrOpcode::Value kShiftOpcode>
284struct ScaleMatcher {
285  explicit ScaleMatcher(Node* node, bool allow_power_of_two_plus_one = false)
286      : scale_(-1), power_of_two_plus_one_(false) {
287    if (node->InputCount() < 2) return;
288    BinopMatcher m(node);
289    if (node->opcode() == kShiftOpcode) {
290      if (m.right().HasValue()) {
291        typename BinopMatcher::RightMatcher::ValueType value =
292            m.right().Value();
293        if (value >= 0 && value <= 3) {
294          scale_ = static_cast<int>(value);
295        }
296      }
297    } else if (node->opcode() == kMulOpcode) {
298      if (m.right().HasValue()) {
299        typename BinopMatcher::RightMatcher::ValueType value =
300            m.right().Value();
301        if (value == 1) {
302          scale_ = 0;
303        } else if (value == 2) {
304          scale_ = 1;
305        } else if (value == 4) {
306          scale_ = 2;
307        } else if (value == 8) {
308          scale_ = 3;
309        } else if (allow_power_of_two_plus_one) {
310          if (value == 3) {
311            scale_ = 1;
312            power_of_two_plus_one_ = true;
313          } else if (value == 5) {
314            scale_ = 2;
315            power_of_two_plus_one_ = true;
316          } else if (value == 9) {
317            scale_ = 3;
318            power_of_two_plus_one_ = true;
319          }
320        }
321      }
322    }
323  }
324
325  bool matches() const { return scale_ != -1; }
326  int scale() const { return scale_; }
327  bool power_of_two_plus_one() const { return power_of_two_plus_one_; }
328
329 private:
330  int scale_;
331  bool power_of_two_plus_one_;
332};
333
334typedef ScaleMatcher<Int32BinopMatcher, IrOpcode::kInt32Mul,
335                     IrOpcode::kWord32Shl> Int32ScaleMatcher;
336typedef ScaleMatcher<Int64BinopMatcher, IrOpcode::kInt64Mul,
337                     IrOpcode::kWord64Shl> Int64ScaleMatcher;
338
339template <class BinopMatcher, IrOpcode::Value AddOpcode,
340          IrOpcode::Value SubOpcode, IrOpcode::Value kMulOpcode,
341          IrOpcode::Value kShiftOpcode>
342struct AddMatcher : public BinopMatcher {
343  static const IrOpcode::Value kAddOpcode = AddOpcode;
344  static const IrOpcode::Value kSubOpcode = SubOpcode;
345  typedef ScaleMatcher<BinopMatcher, kMulOpcode, kShiftOpcode> Matcher;
346
347  AddMatcher(Node* node, bool allow_input_swap)
348      : BinopMatcher(node, allow_input_swap),
349        scale_(-1),
350        power_of_two_plus_one_(false) {
351    Initialize(node, allow_input_swap);
352  }
353  explicit AddMatcher(Node* node)
354      : BinopMatcher(node, node->op()->HasProperty(Operator::kCommutative)),
355        scale_(-1),
356        power_of_two_plus_one_(false) {
357    Initialize(node, node->op()->HasProperty(Operator::kCommutative));
358  }
359
360  bool HasIndexInput() const { return scale_ != -1; }
361  Node* IndexInput() const {
362    DCHECK(HasIndexInput());
363    return this->left().node()->InputAt(0);
364  }
365  int scale() const {
366    DCHECK(HasIndexInput());
367    return scale_;
368  }
369  bool power_of_two_plus_one() const { return power_of_two_plus_one_; }
370
371 private:
372  void Initialize(Node* node, bool allow_input_swap) {
373    Matcher left_matcher(this->left().node(), true);
374    if (left_matcher.matches()) {
375      scale_ = left_matcher.scale();
376      power_of_two_plus_one_ = left_matcher.power_of_two_plus_one();
377      return;
378    }
379
380    if (!allow_input_swap) {
381      return;
382    }
383
384    Matcher right_matcher(this->right().node(), true);
385    if (right_matcher.matches()) {
386      scale_ = right_matcher.scale();
387      power_of_two_plus_one_ = right_matcher.power_of_two_plus_one();
388      this->SwapInputs();
389      return;
390    }
391
392    if (this->right().opcode() == kAddOpcode &&
393        this->left().opcode() != kAddOpcode) {
394      this->SwapInputs();
395    } else if (this->right().opcode() == kSubOpcode &&
396               this->left().opcode() != kSubOpcode) {
397      this->SwapInputs();
398    }
399  }
400
401  int scale_;
402  bool power_of_two_plus_one_;
403};
404
405typedef AddMatcher<Int32BinopMatcher, IrOpcode::kInt32Add, IrOpcode::kInt32Sub,
406                   IrOpcode::kInt32Mul, IrOpcode::kWord32Shl>
407    Int32AddMatcher;
408typedef AddMatcher<Int64BinopMatcher, IrOpcode::kInt64Add, IrOpcode::kInt64Sub,
409                   IrOpcode::kInt64Mul, IrOpcode::kWord64Shl>
410    Int64AddMatcher;
411
412enum DisplacementMode { kPositiveDisplacement, kNegativeDisplacement };
413
414enum class AddressOption : uint8_t {
415  kAllowNone = 0u,
416  kAllowInputSwap = 1u << 0,
417  kAllowScale = 1u << 1,
418  kAllowAll = kAllowInputSwap | kAllowScale
419};
420
421typedef base::Flags<AddressOption, uint8_t> AddressOptions;
422DEFINE_OPERATORS_FOR_FLAGS(AddressOptions);
423
424template <class AddMatcher>
425struct BaseWithIndexAndDisplacementMatcher {
426  BaseWithIndexAndDisplacementMatcher(Node* node, AddressOptions options)
427      : matches_(false),
428        index_(nullptr),
429        scale_(0),
430        base_(nullptr),
431        displacement_(nullptr),
432        displacement_mode_(kPositiveDisplacement) {
433    Initialize(node, options);
434  }
435
436  explicit BaseWithIndexAndDisplacementMatcher(Node* node)
437      : matches_(false),
438        index_(nullptr),
439        scale_(0),
440        base_(nullptr),
441        displacement_(nullptr),
442        displacement_mode_(kPositiveDisplacement) {
443    Initialize(node, AddressOption::kAllowScale |
444                         (node->op()->HasProperty(Operator::kCommutative)
445                              ? AddressOption::kAllowInputSwap
446                              : AddressOption::kAllowNone));
447  }
448
449  bool matches() const { return matches_; }
450  Node* index() const { return index_; }
451  int scale() const { return scale_; }
452  Node* base() const { return base_; }
453  Node* displacement() const { return displacement_; }
454  DisplacementMode displacement_mode() const { return displacement_mode_; }
455
456 private:
457  bool matches_;
458  Node* index_;
459  int scale_;
460  Node* base_;
461  Node* displacement_;
462  DisplacementMode displacement_mode_;
463
464  void Initialize(Node* node, AddressOptions options) {
465    // The BaseWithIndexAndDisplacementMatcher canonicalizes the order of
466    // displacements and scale factors that are used as inputs, so instead of
467    // enumerating all possible patterns by brute force, checking for node
468    // clusters using the following templates in the following order suffices to
469    // find all of the interesting cases (S = index * scale, B = base input, D =
470    // displacement input):
471    // (S + (B + D))
472    // (S + (B + B))
473    // (S + D)
474    // (S + B)
475    // ((S + D) + B)
476    // ((S + B) + D)
477    // ((B + D) + B)
478    // ((B + B) + D)
479    // (B + D)
480    // (B + B)
481    if (node->InputCount() < 2) return;
482    AddMatcher m(node, options & AddressOption::kAllowInputSwap);
483    Node* left = m.left().node();
484    Node* right = m.right().node();
485    Node* displacement = nullptr;
486    Node* base = nullptr;
487    Node* index = nullptr;
488    Node* scale_expression = nullptr;
489    bool power_of_two_plus_one = false;
490    DisplacementMode displacement_mode = kPositiveDisplacement;
491    int scale = 0;
492    if (m.HasIndexInput() && left->OwnedBy(node)) {
493      index = m.IndexInput();
494      scale = m.scale();
495      scale_expression = left;
496      power_of_two_plus_one = m.power_of_two_plus_one();
497      bool match_found = false;
498      if (right->opcode() == AddMatcher::kSubOpcode && right->OwnedBy(node)) {
499        AddMatcher right_matcher(right);
500        if (right_matcher.right().HasValue()) {
501          // (S + (B - D))
502          base = right_matcher.left().node();
503          displacement = right_matcher.right().node();
504          displacement_mode = kNegativeDisplacement;
505          match_found = true;
506        }
507      }
508      if (!match_found) {
509        if (right->opcode() == AddMatcher::kAddOpcode && right->OwnedBy(node)) {
510          AddMatcher right_matcher(right);
511          if (right_matcher.right().HasValue()) {
512            // (S + (B + D))
513            base = right_matcher.left().node();
514            displacement = right_matcher.right().node();
515          } else {
516            // (S + (B + B))
517            base = right;
518          }
519        } else if (m.right().HasValue()) {
520          // (S + D)
521          displacement = right;
522        } else {
523          // (S + B)
524          base = right;
525        }
526      }
527    } else {
528      bool match_found = false;
529      if (left->opcode() == AddMatcher::kSubOpcode && left->OwnedBy(node)) {
530        AddMatcher left_matcher(left);
531        Node* left_left = left_matcher.left().node();
532        Node* left_right = left_matcher.right().node();
533        if (left_matcher.right().HasValue()) {
534          if (left_matcher.HasIndexInput() && left_left->OwnedBy(left)) {
535            // ((S - D) + B)
536            index = left_matcher.IndexInput();
537            scale = left_matcher.scale();
538            scale_expression = left_left;
539            power_of_two_plus_one = left_matcher.power_of_two_plus_one();
540            displacement = left_right;
541            displacement_mode = kNegativeDisplacement;
542            base = right;
543          } else {
544            // ((B - D) + B)
545            index = left_left;
546            displacement = left_right;
547            displacement_mode = kNegativeDisplacement;
548            base = right;
549          }
550          match_found = true;
551        }
552      }
553      if (!match_found) {
554        if (left->opcode() == AddMatcher::kAddOpcode && left->OwnedBy(node)) {
555          AddMatcher left_matcher(left);
556          Node* left_left = left_matcher.left().node();
557          Node* left_right = left_matcher.right().node();
558          if (left_matcher.HasIndexInput() && left_left->OwnedBy(left)) {
559            if (left_matcher.right().HasValue()) {
560              // ((S + D) + B)
561              index = left_matcher.IndexInput();
562              scale = left_matcher.scale();
563              scale_expression = left_left;
564              power_of_two_plus_one = left_matcher.power_of_two_plus_one();
565              displacement = left_right;
566              base = right;
567            } else if (m.right().HasValue()) {
568              // ((S + B) + D)
569              index = left_matcher.IndexInput();
570              scale = left_matcher.scale();
571              scale_expression = left_left;
572              power_of_two_plus_one = left_matcher.power_of_two_plus_one();
573              base = left_right;
574              displacement = right;
575            } else {
576              // (B + B)
577              index = left;
578              base = right;
579            }
580          } else {
581            if (left_matcher.right().HasValue()) {
582              // ((B + D) + B)
583              index = left_left;
584              displacement = left_right;
585              base = right;
586            } else if (m.right().HasValue()) {
587              // ((B + B) + D)
588              index = left_left;
589              base = left_right;
590              displacement = right;
591            } else {
592              // (B + B)
593              index = left;
594              base = right;
595            }
596          }
597        } else {
598          if (m.right().HasValue()) {
599            // (B + D)
600            base = left;
601            displacement = right;
602          } else {
603            // (B + B)
604            base = left;
605            index = right;
606          }
607        }
608      }
609    }
610    int64_t value = 0;
611    if (displacement != nullptr) {
612      switch (displacement->opcode()) {
613        case IrOpcode::kInt32Constant: {
614          value = OpParameter<int32_t>(displacement);
615          break;
616        }
617        case IrOpcode::kInt64Constant: {
618          value = OpParameter<int64_t>(displacement);
619          break;
620        }
621        default:
622          UNREACHABLE();
623          break;
624      }
625      if (value == 0) {
626        displacement = nullptr;
627      }
628    }
629    if (power_of_two_plus_one) {
630      if (base != nullptr) {
631        // If the scale requires explicitly using the index as the base, but a
632        // base is already part of the match, then the (1 << N + 1) scale factor
633        // can't be folded into the match and the entire index * scale
634        // calculation must be computed separately.
635        index = scale_expression;
636        scale = 0;
637      } else {
638        base = index;
639      }
640    }
641    if (!(options & AddressOption::kAllowScale) && scale != 0) {
642      index = scale_expression;
643      scale = 0;
644    }
645    base_ = base;
646    displacement_ = displacement;
647    displacement_mode_ = displacement_mode;
648    index_ = index;
649    scale_ = scale;
650    matches_ = true;
651  }
652};
653
654typedef BaseWithIndexAndDisplacementMatcher<Int32AddMatcher>
655    BaseWithIndexAndDisplacement32Matcher;
656typedef BaseWithIndexAndDisplacementMatcher<Int64AddMatcher>
657    BaseWithIndexAndDisplacement64Matcher;
658
659struct V8_EXPORT_PRIVATE BranchMatcher : public NON_EXPORTED_BASE(NodeMatcher) {
660  explicit BranchMatcher(Node* branch);
661
662  bool Matched() const { return if_true_ && if_false_; }
663
664  Node* Branch() const { return node(); }
665  Node* IfTrue() const { return if_true_; }
666  Node* IfFalse() const { return if_false_; }
667
668 private:
669  Node* if_true_;
670  Node* if_false_;
671};
672
673struct V8_EXPORT_PRIVATE DiamondMatcher
674    : public NON_EXPORTED_BASE(NodeMatcher) {
675  explicit DiamondMatcher(Node* merge);
676
677  bool Matched() const { return branch_; }
678  bool IfProjectionsAreOwned() const {
679    return if_true_->OwnedBy(node()) && if_false_->OwnedBy(node());
680  }
681
682  Node* Branch() const { return branch_; }
683  Node* IfTrue() const { return if_true_; }
684  Node* IfFalse() const { return if_false_; }
685  Node* Merge() const { return node(); }
686
687  Node* TrueInputOf(Node* phi) const {
688    DCHECK(IrOpcode::IsPhiOpcode(phi->opcode()));
689    DCHECK_EQ(3, phi->InputCount());
690    DCHECK_EQ(Merge(), phi->InputAt(2));
691    return phi->InputAt(if_true_ == Merge()->InputAt(0) ? 0 : 1);
692  }
693
694  Node* FalseInputOf(Node* phi) const {
695    DCHECK(IrOpcode::IsPhiOpcode(phi->opcode()));
696    DCHECK_EQ(3, phi->InputCount());
697    DCHECK_EQ(Merge(), phi->InputAt(2));
698    return phi->InputAt(if_true_ == Merge()->InputAt(0) ? 1 : 0);
699  }
700
701 private:
702  Node* branch_;
703  Node* if_true_;
704  Node* if_false_;
705};
706
707}  // namespace compiler
708}  // namespace internal
709}  // namespace v8
710
711#endif  // V8_COMPILER_NODE_MATCHERS_H_
712