MIPS: Specialize FixedTypedArray<> set and get functions to solve unaligned double access.

BUG=
TEST=test-api/FixedFloat64Array
R=dslomov@chromium.org

Review URL: https://codereview.chromium.org/136333011

Patch from Balazs Kilvady <kilvadyb@homejinni.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@18965 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/objects-inl.h

@@ -3675,6 +3675,15 @@ typename Traits::ElementType FixedTypedArray<Traits>::get_scalar(int index) {
   return ptr[index];
 }
 
+
+template<> inline
+FixedTypedArray<Float64ArrayTraits>::ElementType
+    FixedTypedArray<Float64ArrayTraits>::get_scalar(int index) {
+  ASSERT((index >= 0) && (index < this->length()));
+  return READ_DOUBLE_FIELD(this, ElementOffset(index));
+}
+
+
 template <class Traits>
 void FixedTypedArray<Traits>::set(int index, ElementType value) {
   ASSERT((index >= 0) && (index < this->length()));
@@ -3684,6 +3693,14 @@ void FixedTypedArray<Traits>::set(int index, ElementType value) {
 }
 
 
+template<> inline
+void FixedTypedArray<Float64ArrayTraits>::set(
+    int index, Float64ArrayTraits::ElementType value) {
+  ASSERT((index >= 0) && (index < this->length()));
+  WRITE_DOUBLE_FIELD(this, ElementOffset(index), value);
+}
+
+
 template <class Traits>
 MaybeObject* FixedTypedArray<Traits>::get(int index) {
   return Traits::ToObject(GetHeap(), get_scalar(index));

src/objects.h

@@ -4895,8 +4895,12 @@ class FixedTypedArray: public FixedTypedArrayBase {
   // Casting:
   static inline FixedTypedArray<Traits>* cast(Object* obj);
 
+  static inline int ElementOffset(int index) {
+    return kDataOffset + index * sizeof(ElementType);
+  }
+
   static inline int SizeFor(int length) {
-    return kDataOffset + length * sizeof(ElementType);
+    return ElementOffset(length);
   }
 
   inline ElementType get_scalar(int index);