Allow optimizing compiler to compute Math.log using untagged doubles.

src/heap.h

 // Copyright 2010 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 2036 matching lines @@
     return (hash & (kCacheSize - 1));
   }
 
   static Address cache_array_address() {
     // Used to create an external reference.
     return reinterpret_cast<Address>(caches_);
   }
 
   // Allow access to the caches_ array as an ExternalReference.
   friend class ExternalReference;
-  // Inline implementation of the caching.
+  // Inline implementation of the cache.
   friend class TranscendentalCacheStub;
+  friend class TranscendentalCacheSSE2Stub;
 
   static TranscendentalCache* caches_[kNumberOfCaches];
   Element elements_[kCacheSize];
   Type type_;
 };
 
 
 // External strings table is a place where all external strings are
 // registered.  We need to keep track of such strings to properly
 // finalize them.
@@ skipping 36 matching lines @@
   // Return whether this object should be retained. If NULL is returned the
   // object has no references. Otherwise the address of the retained object
   // should be returned as in some GC situations the object has been moved.
   virtual Object* RetainAs(Object* object) = 0;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_H_