Improve range analysis for modulo operations.

src/hydrogen-instructions.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 245 matching lines @@
   Range* Copy(Zone* zone) const {
     Range* result = new(zone) Range(lower_, upper_);
     result->set_can_be_minus_zero(CanBeMinusZero());
     return result;
   }
   int32_t Mask() const;
   void set_can_be_minus_zero(bool b) { can_be_minus_zero_ = b; }
   bool CanBeMinusZero() const { return CanBeZero() && can_be_minus_zero_; }
   bool CanBeZero() const { return upper_ >= 0 && lower_ <= 0; }
   bool CanBeNegative() const { return lower_ < 0; }
+  bool CanBePositive() const { return upper_ > 0; }
   bool Includes(int value) const { return lower_ <= value && upper_ >= value; }
   bool IsMostGeneric() const {
     return lower_ == kMinInt && upper_ == kMaxInt && CanBeMinusZero();
   }
   bool IsInSmiRange() const {
     return lower_ >= Smi::kMinValue && upper_ <= Smi::kMaxValue;
   }
   void KeepOrder();
 #ifdef DEBUG
   void Verify() const;
@@ skipping 6214 matching lines @@
   virtual bool IsDeletable() const { return true; }
 };
 
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_