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

src/hydrogen-instructions.h

Index: src/hydrogen-instructions.h
===================================================================
--- src/hydrogen-instructions.h	(revision 6042)
+++ src/hydrogen-instructions.h	(working copy)
@@ -334,6 +334,8 @@
     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;
@@ -353,7 +355,8 @@
     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);