Line data    Source code

       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 RedundancyElimination final : public AdvancedReducer {
      15             :  public:
      16             :   RedundancyElimination(Editor* editor, Zone* zone);
      17             :   ~RedundancyElimination() final;
      18             : 
      19             :   Reduction Reduce(Node* node) final;
      20             : 
      21             :  private:
      22             :   struct Check {
      23      282672 :     Check(Node* node, Check* next) : node(node), next(next) {}
      24             :     Node* node;
      25             :     Check* next;
      26             :   };
      27             : 
      28             :   class EffectPathChecks final {
      29             :    public:
      30             :     static EffectPathChecks* Copy(Zone* zone, EffectPathChecks const* checks);
      31             :     static EffectPathChecks const* Empty(Zone* zone);
      32             :     bool Equals(EffectPathChecks const* that) const;
      33             :     void Merge(EffectPathChecks const* that);
      34             : 
      35             :     EffectPathChecks const* AddCheck(Zone* zone, Node* node) const;
      36             :     Node* LookupCheck(Node* node) const;
      37             :     Node* LookupBoundsCheckFor(Node* node) const;
      38             : 
      39             :    private:
      40     1071149 :     EffectPathChecks(Check* head, size_t size) : head_(head), size_(size) {}
      41             : 
      42             :     // We keep track of the list length so that we can find the longest
      43             :     // common tail easily.
      44             :     Check* head_;
      45             :     size_t size_;
      46             :   };
      47             : 
      48             :   class PathChecksForEffectNodes final {
      49             :    public:
      50             :     explicit PathChecksForEffectNodes(Zone* zone) : info_for_node_(zone) {}
      51             :     EffectPathChecks const* Get(Node* node) const;
      52             :     void Set(Node* node, EffectPathChecks const* checks);
      53             : 
      54             :    private:
      55             :     ZoneVector<EffectPathChecks const*> info_for_node_;
      56             :   };
      57             : 
      58             :   Reduction ReduceCheckNode(Node* node);
      59             :   Reduction ReduceEffectPhi(Node* node);
      60             :   Reduction ReduceStart(Node* node);
      61             :   Reduction ReduceOtherNode(Node* node);
      62             : 
      63             :   Reduction TakeChecksFromFirstEffect(Node* node);
      64             :   Reduction UpdateChecks(Node* node, EffectPathChecks const* checks);
      65             : 
      66             :   Reduction TryReuseBoundsCheckForFirstInput(Node* node);
      67             : 
      68             :   Zone* zone() const { return zone_; }
      69             : 
      70             :   PathChecksForEffectNodes node_checks_;
      71             :   Zone* const zone_;
      72             : 
      73             :   DISALLOW_COPY_AND_ASSIGN(RedundancyElimination);
      74             : };
      75             : 
      76             : }  // namespace compiler
      77             : }  // namespace internal
      78             : }  // namespace v8
      79             : 
      80             : #endif  // V8_COMPILER_REDUNDANCY_ELIMINATION_H_