Better range information for logical shift right >>>.

src/hydrogen-instructions.h

 // Copyright 2011 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 234 matching lines @@
     Intersect(other);
     next_ = other;
   }
 
   void Intersect(Range* other);
   void Union(Range* other);
 
   void AddConstant(int32_t value);
   void Sar(int32_t value);
   void Shl(int32_t value);
+  void Shr(int32_t value);

[William Hesse, 2011/07/25 13:27:03]

Unimplemented.

   bool AddAndCheckOverflow(Range* other);
   bool SubAndCheckOverflow(Range* other);
   bool MulAndCheckOverflow(Range* other);
 
  private:
   int32_t lower_;
   int32_t upper_;
   Range* next_;
   bool can_be_minus_zero_;
 };
@@ skipping 2788 matching lines @@
  protected:
   virtual bool DataEquals(HValue* other) { return true; }
 };
 
 
 class HShr: public HBitwiseBinaryOperation {
  public:
   HShr(HValue* context, HValue* left, HValue* right)
       : HBitwiseBinaryOperation(context, left, right) { }
 
+  virtual Range* InferRange();
   virtual HType CalculateInferredType();
 
   DECLARE_CONCRETE_INSTRUCTION(Shr)
 
  protected:
   virtual bool DataEquals(HValue* other) { return true; }
 };
 
 
 class HSar: public HBitwiseBinaryOperation {
@@ skipping 1117 matching lines @@
 
   DECLARE_CONCRETE_INSTRUCTION(In)
 };
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_