Propagate reaching definitions to the instuctions of a block.

src/data-flow.h

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 111 matching lines @@
 
   bool Equals(const BitVector& other) {
     for (int i = 0; i < data_length_; i++) {
       if (data_[i] != other.data_[i]) return false;
     }
     return true;
   }
 
   int length() const { return length_; }
 
+#ifdef DEBUG
+  void Print();
+#endif
+
  private:
   int length_;
   int data_length_;
   uint32_t* data_;
 };
 
 
 // Simple fixed-capacity list-based worklist (managed as a queue) of
 // pointers to T.
 template<typename T>
@@ skipping 86 matching lines @@
   int number() { return number_; }
   void set_number(int number) { number_ = number; }
 
   // Functions used by data-flow analyses.
   virtual void InitializeReachingDefinitions(int definition_count,
                                              List<BitVector*>* variables,
                                              WorkList<Node>* worklist,
                                              bool mark);
   virtual void ComputeRDOut(BitVector* result) = 0;
   virtual void UpdateRDIn(WorkList<Node>* worklist, bool mark) = 0;
+  virtual void PropagateReachingDefinitions(List<BitVector*>* variables);
 
 #ifdef DEBUG
   void AssignNodeNumber();
   void PrintReachingDefinitions();
   virtual void PrintText() = 0;
 #endif
 
  protected:
   ReachingDefinitionsData rd_;
 
@@ skipping 69 matching lines @@
   void Traverse(bool mark,
                 ZoneList<Node*>* preorder,
                 ZoneList<Node*>* postorder);
 
   void InitializeReachingDefinitions(int definition_count,
                                      List<BitVector*>* variables,
                                      WorkList<Node>* worklist,
                                      bool mark);
   void ComputeRDOut(BitVector* result);
   void UpdateRDIn(WorkList<Node>* worklist, bool mark);
+  void PropagateReachingDefinitions(List<BitVector*>* variables);
 
 #ifdef DEBUG
   void PrintText();
 #endif
 
  private:
   Node* predecessor_;
   Node* successor_;
   ZoneList<AstNode*> instructions_;
 
@@ skipping 321 matching lines @@
   List<BitVector*> variables_;
 
   DISALLOW_COPY_AND_ASSIGN(ReachingDefinitions);
 };
 
 
 } }  // namespace v8::internal
 
 
 #endif  // V8_DATAFLOW_H_