Check elimination improvement: propagation of state through phis is supported, CheckMap narrowing i…

src/hydrogen.h

 // Copyright 2012 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 94 matching lines @@
   void DetachLoopInformation();
   bool IsLoopHeader() const { return loop_information() != NULL; }
   bool IsStartBlock() const { return block_id() == 0; }
   void PostProcessLoopHeader(IterationStatement* stmt);
 
   bool IsFinished() const { return end_ != NULL; }
   void AddPhi(HPhi* phi);
   void RemovePhi(HPhi* phi);
   void AddInstruction(HInstruction* instr, int position);
   bool Dominates(HBasicBlock* other) const;
+  bool EqualToOrDominates(HBasicBlock* other) const;
   int LoopNestingDepth() const;
 
   void SetInitialEnvironment(HEnvironment* env);
   void ClearEnvironment() {
     ASSERT(IsFinished());
     ASSERT(end()->SuccessorCount() == 0);
     last_environment_ = NULL;
   }
   bool HasEnvironment() const { return last_environment_ != NULL; }
   void UpdateEnvironment(HEnvironment* env);
@@ skipping 2571 matching lines @@
   }
 
  private:
   HGraphBuilder* builder_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_H_