1 // Copyright 2016 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_REDUNDANCY_ELIMINATION_H_ 6 #define V8_COMPILER_REDUNDANCY_ELIMINATION_H_ 7 8 #include "src/compiler/graph-reducer.h" 9 10 namespace v8 { 11 namespace internal { 12 namespace compiler { 13 14 class V8_EXPORT_PRIVATE RedundancyElimination final : public AdvancedReducer { 15 public: 16 RedundancyElimination(Editor* editor, Zone* zone); 17 ~RedundancyElimination() final; 18 RedundancyElimination(const RedundancyElimination&) = delete; 19 RedundancyElimination& operator=(const RedundancyElimination&) = delete; 20 reducer_name()21 const char* reducer_name() const override { return "RedundancyElimination"; } 22 23 Reduction Reduce(Node* node) final; 24 25 private: 26 struct Check { CheckCheck27 Check(Node* node, Check* next) : node(node), next(next) {} 28 Node* node; 29 Check* next; 30 }; 31 32 class EffectPathChecks final { 33 public: 34 static EffectPathChecks* Copy(Zone* zone, EffectPathChecks const* checks); 35 static EffectPathChecks const* Empty(Zone* zone); 36 bool Equals(EffectPathChecks const* that) const; 37 void Merge(EffectPathChecks const* that); 38 39 EffectPathChecks const* AddCheck(Zone* zone, Node* node) const; 40 Node* LookupCheck(Node* node) const; 41 Node* LookupBoundsCheckFor(Node* node) const; 42 43 private: 44 friend Zone; 45 EffectPathChecks(Check * head,size_t size)46 EffectPathChecks(Check* head, size_t size) : head_(head), size_(size) {} 47 48 // We keep track of the list length so that we can find the longest 49 // common tail easily. 50 Check* head_; 51 size_t size_; 52 }; 53 54 class PathChecksForEffectNodes final { 55 public: PathChecksForEffectNodes(Zone * zone)56 explicit PathChecksForEffectNodes(Zone* zone) : info_for_node_(zone) {} 57 EffectPathChecks const* Get(Node* node) const; 58 void Set(Node* node, EffectPathChecks const* checks); 59 60 private: 61 ZoneVector<EffectPathChecks const*> info_for_node_; 62 }; 63 64 Reduction ReduceCheckNode(Node* node); 65 Reduction ReduceEffectPhi(Node* node); 66 Reduction ReduceSpeculativeNumberComparison(Node* node); 67 Reduction ReduceSpeculativeNumberOperation(Node* node); 68 Reduction ReduceStart(Node* node); 69 Reduction ReduceOtherNode(Node* node); 70 71 Reduction TakeChecksFromFirstEffect(Node* node); 72 Reduction UpdateChecks(Node* node, EffectPathChecks const* checks); 73 zone()74 Zone* zone() const { return zone_; } 75 76 PathChecksForEffectNodes node_checks_; 77 Zone* const zone_; 78 }; 79 80 } // namespace compiler 81 } // namespace internal 82 } // namespace v8 83 84 #endif // V8_COMPILER_REDUNDANCY_ELIMINATION_H_ 85