Use SameValueZero for Map and Set

src/objects.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "v8.h"
 
 #include "accessors.h"
 #include "allocation-site-scopes.h"
 #include "api.h"
 #include "arguments.h"
@@ skipping 957 matching lines @@
     // SameValue(0.0, -0.0) is false.
     return (this_value != 0) || ((1 / this_value) == (1 / other_value));
   }
   if (IsString() && other->IsString()) {
     return String::cast(this)->Equals(String::cast(other));
   }
   return false;
 }
 
 
+bool Object::SameValueZero(Object* other) {
+  if (other == this) return true;
+
+  // The object is either a number, a name, an odd-ball,
+  // a real JS object, or a Harmony proxy.
+  if (IsNumber() && other->IsNumber()) {
+    double this_value = Number();
+    double other_value = other->Number();
+    // +0 == -0 is true
+    return this_value == other_value
+        || (std::isnan(this_value) && std::isnan(other_value));
+  }
+  if (IsString() && other->IsString()) {
+    return String::cast(this)->Equals(String::cast(other));
+  }
+  return false;
+}
+
+
 void Object::ShortPrint(FILE* out) {
   HeapStringAllocator allocator;
   StringStream accumulator(&allocator);
   ShortPrint(&accumulator);
   accumulator.OutputToFile(out);
 }
 
 
 void Object::ShortPrint(StringStream* accumulator) {
   if (IsSmi()) {
@@ skipping 15334 matching lines @@
   ASSERT(!IsObsolete());
 
   DisallowHeapAllocation no_gc;
   ASSERT(!key->IsTheHole());
   Object* hash = key->GetHash();
   if (hash->IsUndefined()) return kNotFound;
   for (int entry = HashToEntry(Smi::cast(hash)->value());
        entry != kNotFound;
        entry = ChainAt(entry)) {
     Object* candidate = KeyAt(entry);
-    if (candidate->SameValue(*key))
+    if (candidate->SameValueZero(*key))
       return entry;
   }
   return kNotFound;
 }
 
 
 template<class Derived, class Iterator, int entrysize>
 int OrderedHashTable<Derived, Iterator, entrysize>::AddEntry(int hash) {
   ASSERT(!IsObsolete());
 
@@ skipping 885 matching lines @@
 #define ERROR_MESSAGES_TEXTS(C, T) T,
   static const char* error_messages_[] = {
       ERROR_MESSAGES_LIST(ERROR_MESSAGES_TEXTS)
   };
 #undef ERROR_MESSAGES_TEXTS
   return error_messages_[reason];
 }
 
 
 } }  // namespace v8::internal