[objects] seed NumberDictionary (only ia32 now)

src/utils.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 236 matching lines @@
     return static_cast<T>((value & kMask) >> shift);
   }
 };
 
 
 // ----------------------------------------------------------------------------
 // Hash function.
 
 // Thomas Wang, Integer Hash Functions.
 // http://www.concentric.net/~Ttwang/tech/inthash.htm
-inline uint32_t ComputeIntegerHash(uint32_t key) {
+inline uint32_t ComputeIntegerHash(uint32_t key, uint32_t seed = 0) {

[Erik Corry, 2012/01/09 23:52:48]

Why do we need this default argument?

[indutny, 2012/01/10 06:02:39]

Because it's used alot in other places like profiler, debugger, frames.cc . They
should not care about that.

   uint32_t hash = key;
+  hash = hash ^ seed;
   hash = ~hash + (hash << 15);  // hash = (hash << 15) - hash - 1;
   hash = hash ^ (hash >> 12);
   hash = hash + (hash << 2);
   hash = hash ^ (hash >> 4);
   hash = hash * 2057;  // hash = (hash + (hash << 3)) + (hash << 11);
   hash = hash ^ (hash >> 16);
   return hash;
 }
 
 
@@ skipping 669 matching lines @@
     ASSERT(element < static_cast<int>(sizeof(T) * CHAR_BIT));
     return 1 << element;
   }
 
   T bits_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_UTILS_H_