V8: Add utility functions to check SameValue and SameValueZero.

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 <iomanip>
 #include <sstream>
 
 #include "src/v8.h"
 
 #include "src/accessors.h"
@@ skipping 665 matching lines @@
   return JSReceiver::GetOrCreateIdentityHash(Handle<JSReceiver>::cast(object));
 }
 
 
 bool Object::SameValue(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();
-    bool equal = this_value == other_value;
-    // SameValue(NaN, NaN) is true.
-    if (!equal) return std::isnan(this_value) && std::isnan(other_value);
-    // SameValue(0.0, -0.0) is false.
-    return (this_value != 0) || ((1 / this_value) == (1 / other_value));
+    return v8::internal::SameValue(Number(), other->Number());
   }
   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));
+    return v8::internal::SameValueZero(Number(), other->Number());
   }
   if (IsString() && other->IsString()) {
     return String::cast(this)->Equals(String::cast(other));
   }
   return false;
 }
 
 
 void Object::ShortPrint(FILE* out) {
   OFStream os(out);
@@ skipping 15398 matching lines @@
                                             Handle<Object> new_value) {
   if (cell->value() != *new_value) {
     cell->set_value(*new_value);
     Isolate* isolate = cell->GetIsolate();
     cell->dependent_code()->DeoptimizeDependentCodeGroup(
         isolate, DependentCode::kPropertyCellChangedGroup);
   }
 }
 }  // namespace internal
 }  // namespace v8