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

src/objects-inl.h

 // Copyright 2012 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 3657 matching lines @@
 
 
 template <class Traits>
 typename Traits::ElementType FixedTypedArray<Traits>::get_scalar(int index) {
   ASSERT((index >= 0) && (index < this->length()));
   ElementType* ptr = reinterpret_cast<ElementType*>(
       FIELD_ADDR(this, kDataOffset));
   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, FixedTypedArray<Float64ArrayTraits>::SizeFor(index));

[Dmitry Lomov (no reviews), 2014/01/30 16:55:22]

I am not too happy with using SizeFor here - it does not convey the intent,
although it does do the right thing. Could you add an ElementOffset function to
FixedTypedArray, and use it here?

[kilvadyb, 2014/01/30 18:27:05]

Done.

+}
+
+
 template <class Traits>
 void FixedTypedArray<Traits>::set(int index, ElementType value) {
   ASSERT((index >= 0) && (index < this->length()));
   ElementType* ptr = reinterpret_cast<ElementType*>(
       FIELD_ADDR(this, kDataOffset));
   ptr[index] = value;
 }
 
 
+template<> inline
+void FixedTypedArray<Float64ArrayTraits>::set(
+    int index, Float64ArrayTraits::ElementType value) {
+  ASSERT((index >= 0) && (index < this->length()));
+  WRITE_DOUBLE_FIELD(
+      this, FixedTypedArray<Float64ArrayTraits>::SizeFor(index), value);

[Dmitry Lomov (no reviews), 2014/01/30 16:55:22]

Ditto

[kilvadyb, 2014/01/30 18:27:05]

Done.

+}
+
+
 template <class Traits>
 MaybeObject* FixedTypedArray<Traits>::get(int index) {
   return Traits::ToObject(GetHeap(), get_scalar(index));
 }
 
 template <class Traits>
 MaybeObject* FixedTypedArray<Traits>::SetValue(uint32_t index, Object* value) {
   ElementType cast_value = Traits::defaultValue();
   if (index < static_cast<uint32_t>(length())) {
     if (value->IsSmi()) {
@@ skipping 3090 matching lines @@
 #undef READ_UINT32_FIELD
 #undef WRITE_UINT32_FIELD
 #undef READ_SHORT_FIELD
 #undef WRITE_SHORT_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_INL_H_