Avoid convertion to double when it is not needed.

R=rossberg@chromium.org

Review URL: https://codereview.chromium.org/15162002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14664 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/factory.h

@@ -266,10 +266,12 @@ class Factory {
                                   PretenureFlag pretenure = NOT_TENURED);
   Handle<Object> NewNumberFromUint(uint32_t value,
                                   PretenureFlag pretenure = NOT_TENURED);
-
+  inline Handle<Object> NewNumberFromSize(size_t value,
+                                   PretenureFlag pretenure = NOT_TENURED);
   Handle<HeapNumber> NewHeapNumber(double value,
                                    PretenureFlag pretenure = NOT_TENURED);
 
+
   // These objects are used by the api to create env-independent data
   // structures in the heap.
   Handle<JSObject> NewNeanderObject();
@@ -539,6 +541,18 @@ class Factory {
 };
 
 
+Handle<Object> Factory::NewNumberFromSize(size_t value,
+                                          PretenureFlag pretenure) {
+  if (Smi::IsValid(static_cast<intptr_t>(value))) {
+    return Handle<Object>(Smi::FromIntptr(static_cast<intptr_t>(value)),
+                          isolate());
+  } else {
+    return NewNumber(static_cast<double>(value), pretenure);
+  }
+}
+
+
+
 } }  // namespace v8::internal
 
 #endif  // V8_FACTORY_H_

src/runtime.cc

@@ -857,9 +857,9 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_TypedArrayInitialize) {
   ASSERT(byte_length % elementSize == 0);
   size_t length = byte_length / elementSize;
 
-  Handle<Object> length_obj =
-      isolate->factory()->NewNumber(static_cast<double>(length));
+  Handle<Object> length_obj = isolate->factory()->NewNumberFromSize(length);
   holder->set_length(*length_obj);
+
   Handle<ExternalArray> elements =
       isolate->factory()->NewExternalArray(
           static_cast<int>(length), arrayType,