Implement support for getters/setter on FixedDoubleArrays.

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 341f929750465214f68bb48a20baaaf2e8c9a50f..fcfbd1c6c3a4f08b2cc9e4d96e7620cc33eb2f8b 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -3656,6 +3656,7 @@ MaybeObject* JSObject::DefineGetterSetter(String* name,
   if (is_element) {
     switch (GetElementsKind()) {
       case FAST_ELEMENTS:
+      case FAST_DOUBLE_ELEMENTS:
         break;
       case EXTERNAL_PIXEL_ELEMENTS:
       case EXTERNAL_BYTE_ELEMENTS:
@@ -3666,7 +3667,6 @@ MaybeObject* JSObject::DefineGetterSetter(String* name,
       case EXTERNAL_UNSIGNED_INT_ELEMENTS:
       case EXTERNAL_FLOAT_ELEMENTS:
       case EXTERNAL_DOUBLE_ELEMENTS:
-      case FAST_DOUBLE_ELEMENTS:
         // Ignore getters and setters on pixel and external array
         // elements.
         return heap->undefined_value();
@@ -3905,6 +3905,7 @@ MaybeObject* JSObject::DefineAccessor(AccessorInfo* info) {
     // Accessors overwrite previous callbacks (cf. with getters/setters).
     switch (GetElementsKind()) {
       case FAST_ELEMENTS:
+      case FAST_DOUBLE_ELEMENTS:
         break;
       case EXTERNAL_PIXEL_ELEMENTS:
       case EXTERNAL_BYTE_ELEMENTS:
@@ -3915,7 +3916,6 @@ MaybeObject* JSObject::DefineAccessor(AccessorInfo* info) {
       case EXTERNAL_UNSIGNED_INT_ELEMENTS:
       case EXTERNAL_FLOAT_ELEMENTS:
       case EXTERNAL_DOUBLE_ELEMENTS:
-      case FAST_DOUBLE_ELEMENTS:
         // Ignore getters and setters on pixel and external array
         // elements.
         return isolate->heap()->undefined_value();
@@ -4688,6 +4688,9 @@ MaybeObject* FixedArray::AddKeysFromJSArray(JSArray* array) {
   switch (array->GetElementsKind()) {
     case JSObject::FAST_ELEMENTS:
       return UnionOfKeys(FixedArray::cast(array->elements()));
+    case JSObject::FAST_DOUBLE_ELEMENTS:
+      UNIMPLEMENTED();
+      break;
     case JSObject::DICTIONARY_ELEMENTS: {
       NumberDictionary* dict = array->element_dictionary();
       int size = dict->NumberOfElements();
@@ -4722,7 +4725,6 @@ MaybeObject* FixedArray::AddKeysFromJSArray(JSArray* array) {
     case JSObject::EXTERNAL_FLOAT_ELEMENTS:
     case JSObject::EXTERNAL_DOUBLE_ELEMENTS:
     case JSObject::EXTERNAL_PIXEL_ELEMENTS:
-    case JSObject::FAST_DOUBLE_ELEMENTS:
       break;
   }
   UNREACHABLE();
@@ -8038,6 +8040,17 @@ JSObject::LocalElementType JSObject::HasLocalElement(uint32_t index) {
       }
       break;
     }
+    case FAST_DOUBLE_ELEMENTS: {
+      uint32_t length = IsJSArray() ?
+          static_cast<uint32_t>
+              (Smi::cast(JSArray::cast(this)->length())->value()) :
+          static_cast<uint32_t>(FixedDoubleArray::cast(elements())->length());
+      if ((index < length) &&
+          !FixedDoubleArray::cast(elements())->is_the_hole(index)) {
+        return FAST_ELEMENT;
+      }
+      break;
+    }
     case EXTERNAL_PIXEL_ELEMENTS: {
       ExternalPixelArray* pixels = ExternalPixelArray::cast(elements());
       if (index < static_cast<uint32_t>(pixels->length())) return FAST_ELEMENT;
@@ -8055,9 +8068,6 @@ JSObject::LocalElementType JSObject::HasLocalElement(uint32_t index) {
       if (index < static_cast<uint32_t>(array->length())) return FAST_ELEMENT;
       break;
     }
-    case FAST_DOUBLE_ELEMENTS:
-      UNREACHABLE();
-      break;
     case DICTIONARY_ELEMENTS: {
       if (element_dictionary()->FindEntry(index) !=
           NumberDictionary::kNotFound) {