Store offset between fixed typed array base and data start in object

src/elements-kind.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/elements-kind.h"
 
 #include "src/api.h"
 #include "src/base/lazy-instance.h"
 #include "src/elements.h"
 #include "src/objects.h"
@@ skipping 35 matching lines @@
     case DICTIONARY_ELEMENTS:
     case FAST_SLOPPY_ARGUMENTS_ELEMENTS:
     case SLOW_SLOPPY_ARGUMENTS_ELEMENTS:
       return kPointerSizeLog2;
   }
   UNREACHABLE();
   return 0;
 }
 
 
+static bool IsTypedArrayElementsKind(ElementsKind elements_kind) {
+  return IsFixedTypedArrayElementsKind(elements_kind) ||
+         IsExternalArrayElementsKind(elements_kind);
+}
+
+
 int GetDefaultHeaderSizeForElementsKind(ElementsKind elements_kind) {
   STATIC_ASSERT(FixedArray::kHeaderSize == FixedDoubleArray::kHeaderSize);
 
-  if (IsExternalArrayElementsKind(elements_kind)) {
+  if (IsTypedArrayElementsKind(elements_kind)) {
     return 0;
-  } else if (IsFixedTypedArrayElementsKind(elements_kind)) {
-    return FixedTypedArrayBase::kDataOffset - kHeapObjectTag;
   } else {
     return FixedArray::kHeaderSize - kHeapObjectTag;
   }
 }
 
 
 const char* ElementsKindToString(ElementsKind kind) {
   ElementsAccessor* accessor = ElementsAccessor::ForKind(kind);
   return accessor->name();
 }
@@ skipping 55 matching lines @@
     TYPED_ARRAYS(FIXED_TYPED_ARRAY_CASE)
 #undef FIXED_TYPED_ARRAY_CASE
     default: {
       int index = GetSequenceIndexFromFastElementsKind(kind);
       return GetFastElementsKindFromSequenceIndex(index + 1);
     }
   }
 }
 
 
-static bool IsTypedArrayElementsKind(ElementsKind elements_kind) {
-  return IsFixedTypedArrayElementsKind(elements_kind) ||
-      IsExternalArrayElementsKind(elements_kind);
-}
-
-
 static inline bool IsFastTransitionTarget(ElementsKind elements_kind) {
   return IsFastElementsKind(elements_kind) ||
       elements_kind == DICTIONARY_ELEMENTS;
 }
 
 bool IsMoreGeneralElementsKindTransition(ElementsKind from_kind,
                                          ElementsKind to_kind) {
   if (IsTypedArrayElementsKind(from_kind) ||
       IsTypedArrayElementsKind(to_kind)) {
     switch (from_kind) {
@@ skipping 28 matching lines @@
       default:
         return false;
     }
   }
   return false;
 }
 
 
 }  // namespace internal
 }  // namespace v8