Fix bugs in the range analysis for integers....

src/hydrogen-instructions.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 316 matching lines @@
     int old_upper = upper_;
     lower_ = lower_ << bits;
     upper_ = upper_ << bits;
     if (old_lower != lower_ >> bits || old_upper != upper_ >> bits) {
       upper_ = kMaxInt;
       lower_ = kMinInt;
     }
     set_can_be_minus_zero(false);
   }
 
+  void AddConstant(int32_t value);

[Vyacheslav Egorov (Chromium), 2010/12/16 17:48:10]

Comment what this function does to this Range.

+
   void StackUpon(Range* other) {
     Intersect(other);
     next_ = other;
   }
 
   void Intersect(Range* other) {
     upper_ = Min(upper_, other->upper_);
     lower_ = Max(lower_, other->lower_);
     bool b = CanBeMinusZero() && other->CanBeMinusZero();
     set_can_be_minus_zero(b);
   }
 
   void Union(Range* other) {
     upper_ = Max(upper_, other->upper_);
     lower_ = Min(lower_, other->lower_);
     bool b = CanBeMinusZero() || other->CanBeMinusZero();
     set_can_be_minus_zero(b);
   }
 
-  void Add(int32_t value);
+  // Compute a new result range and return true, if the operation
+  // can overflow.
   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 2543 matching lines @@
   HValue* object() const { return left(); }
   HValue* key() const { return right(); }
 };
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_