Improve check elimination with branch sensitivity on HCompareObjectEqAndBranch.

src/unique.h

 // Copyright 2013 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 260 matching lines @@
       }
     }
 
     while (i < this->size_) out->array_[k++] = this->array_[i++];
     while (j < that->size_) out->array_[k++] = that->array_[j++];
 
     out->size_ = k;
     return out;
   }
 
-  // Makes an exact copy of this set. O(|this| + |that|).
+  // Makes an exact copy of this set. O(|this|).
   UniqueSet<T>* Copy(Zone* zone) const {
     UniqueSet<T>* copy = new(zone) UniqueSet<T>();
     copy->size_ = this->size_;
     copy->capacity_ = this->size_;
     copy->array_ = zone->NewArray<Unique<T> >(this->size_);
     memcpy(copy->array_, this->array_, this->size_ * sizeof(Unique<T>));
     return copy;
   }
 
   void Clear() {
@@ skipping 31 matching lines @@
       capacity_ = new_capacity;
       array_ = new_array;
     }
   }
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_UNIQUE_H_