Reland of "Remove ExternalArray, derived types, and element kinds"

src/heap/heap.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/v8.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/base/bits.h"
 #include "src/base/once.h"
@@ skipping 2482 matching lines @@
 
   static inline void EvacuateFixedTypedArray(Map* map, HeapObject** slot,
                                              HeapObject* object) {
     int object_size = reinterpret_cast<FixedTypedArrayBase*>(object)->size();
     EvacuateObject<DATA_OBJECT, kWordAligned>(map, slot, object, object_size);
 
     MapWord map_word = object->map_word();
     DCHECK(map_word.IsForwardingAddress());
     FixedTypedArrayBase* target =
         reinterpret_cast<FixedTypedArrayBase*>(map_word.ToForwardingAddress());
-    target->set_base_pointer(target, SKIP_WRITE_BARRIER);
+    if (target->base_pointer() != Smi::FromInt(0))
+      target->set_base_pointer(target, SKIP_WRITE_BARRIER);
   }
 
 
   static inline void EvacuateFixedFloat64Array(Map* map, HeapObject** slot,
                                                HeapObject* object) {
     int object_size = reinterpret_cast<FixedFloat64Array*>(object)->size();
     EvacuateObject<DATA_OBJECT, kDoubleAligned>(map, slot, object, object_size);
 
     MapWord map_word = object->map_word();
     DCHECK(map_word.IsForwardingAddress());
     FixedTypedArrayBase* target =
         reinterpret_cast<FixedTypedArrayBase*>(map_word.ToForwardingAddress());
-    target->set_base_pointer(target, SKIP_WRITE_BARRIER);
+    if (target->base_pointer() != Smi::FromInt(0))
+      target->set_base_pointer(target, SKIP_WRITE_BARRIER);
   }
 
 
   static inline void EvacuateJSArrayBuffer(Map* map, HeapObject** slot,
                                            HeapObject* object) {
     ObjectEvacuationStrategy<POINTER_OBJECT>::Visit(map, slot, object);
 
     Heap* heap = map->GetHeap();
     MapWord map_word = object->map_word();
     DCHECK(map_word.IsForwardingAddress());
@@ skipping 470 matching lines @@
                                                 ExternalOneByteString::kSize);
       if (!allocation.To(&obj)) return false;
       set_native_source_string_map(Map::cast(obj));
     }
 
     ALLOCATE_VARSIZE_MAP(FIXED_DOUBLE_ARRAY_TYPE, fixed_double_array)
     ALLOCATE_VARSIZE_MAP(BYTE_ARRAY_TYPE, byte_array)
     ALLOCATE_VARSIZE_MAP(BYTECODE_ARRAY_TYPE, bytecode_array)
     ALLOCATE_VARSIZE_MAP(FREE_SPACE_TYPE, free_space)
 
-#define ALLOCATE_EXTERNAL_ARRAY_MAP(Type, type, TYPE, ctype, size) \
-  ALLOCATE_MAP(EXTERNAL_##TYPE##_ARRAY_TYPE, ExternalArray::kSize, \
-               external_##type##_array)
-
-    TYPED_ARRAYS(ALLOCATE_EXTERNAL_ARRAY_MAP)
-#undef ALLOCATE_EXTERNAL_ARRAY_MAP
-
 #define ALLOCATE_FIXED_TYPED_ARRAY_MAP(Type, type, TYPE, ctype, size) \
   ALLOCATE_VARSIZE_MAP(FIXED_##TYPE##_ARRAY_TYPE, fixed_##type##_array)
 
     TYPED_ARRAYS(ALLOCATE_FIXED_TYPED_ARRAY_MAP)
 #undef ALLOCATE_FIXED_TYPED_ARRAY_MAP
 
     ALLOCATE_VARSIZE_MAP(FIXED_ARRAY_TYPE, sloppy_arguments_elements)
 
     ALLOCATE_VARSIZE_MAP(CODE_TYPE, code)
 
@@ skipping 45 matching lines @@
 
       BytecodeArray* bytecode_array;
       AllocationResult allocation =
           AllocateBytecodeArray(0, nullptr, kPointerSize);
       if (!allocation.To(&bytecode_array)) {
         return false;
       }
       set_empty_bytecode_array(bytecode_array);
     }
 
-#define ALLOCATE_EMPTY_EXTERNAL_ARRAY(Type, type, TYPE, ctype, size)  \
-  {                                                                   \
-    ExternalArray* obj;                                               \
-    if (!AllocateEmptyExternalArray(kExternal##Type##Array).To(&obj)) \
-      return false;                                                   \
-    set_empty_external_##type##_array(obj);                           \
-  }
-
-    TYPED_ARRAYS(ALLOCATE_EMPTY_EXTERNAL_ARRAY)
-#undef ALLOCATE_EMPTY_EXTERNAL_ARRAY
-
 #define ALLOCATE_EMPTY_FIXED_TYPED_ARRAY(Type, type, TYPE, ctype, size) \
   {                                                                     \
     FixedTypedArrayBase* obj;                                           \
     if (!AllocateEmptyFixedTypedArray(kExternal##Type##Array).To(&obj)) \
       return false;                                                     \
     set_empty_fixed_##type##_array(obj);                                \
   }
 
     TYPED_ARRAYS(ALLOCATE_EMPTY_FIXED_TYPED_ARRAY)
 #undef ALLOCATE_EMPTY_FIXED_TYPED_ARRAY
@@ skipping 595 matching lines @@
       // releasing an evacuation candidate due to a slots buffer overflow
       // results in lost pages.
       mark_compact_collector()->RecordSlot(slot, slot, *slot,
                                            SlotsBuffer::IGNORE_OVERFLOW);
     }
     allocation_sites_scratchpad_length_++;
   }
 }
 
 
-Map* Heap::MapForExternalArrayType(ExternalArrayType array_type) {
-  return Map::cast(roots_[RootIndexForExternalArrayType(array_type)]);
-}
-
-
-Heap::RootListIndex Heap::RootIndexForExternalArrayType(
-    ExternalArrayType array_type) {
-  switch (array_type) {
-#define ARRAY_TYPE_TO_ROOT_INDEX(Type, type, TYPE, ctype, size) \
-  case kExternal##Type##Array:                                  \
-    return kExternal##Type##ArrayMapRootIndex;
-
-    TYPED_ARRAYS(ARRAY_TYPE_TO_ROOT_INDEX)
-#undef ARRAY_TYPE_TO_ROOT_INDEX
-
-    default:
-      UNREACHABLE();
-      return kUndefinedValueRootIndex;
-  }
-}
-
 
 Map* Heap::MapForFixedTypedArray(ExternalArrayType array_type) {
   return Map::cast(roots_[RootIndexForFixedTypedArray(array_type)]);
 }
 
 
 Heap::RootListIndex Heap::RootIndexForFixedTypedArray(
     ExternalArrayType array_type) {
   switch (array_type) {
 #define ARRAY_TYPE_TO_ROOT_INDEX(Type, type, TYPE, ctype, size) \
   case kExternal##Type##Array:                                  \
     return kFixed##Type##ArrayMapRootIndex;
 
     TYPED_ARRAYS(ARRAY_TYPE_TO_ROOT_INDEX)
 #undef ARRAY_TYPE_TO_ROOT_INDEX
 
     default:
       UNREACHABLE();
       return kUndefinedValueRootIndex;
   }
 }
 
 
-Heap::RootListIndex Heap::RootIndexForEmptyExternalArray(
-    ElementsKind elementsKind) {
-  switch (elementsKind) {
-#define ELEMENT_KIND_TO_ROOT_INDEX(Type, type, TYPE, ctype, size) \
-  case EXTERNAL_##TYPE##_ELEMENTS:                                \
-    return kEmptyExternal##Type##ArrayRootIndex;
-
-    TYPED_ARRAYS(ELEMENT_KIND_TO_ROOT_INDEX)
-#undef ELEMENT_KIND_TO_ROOT_INDEX
-
-    default:
-      UNREACHABLE();
-      return kUndefinedValueRootIndex;
-  }
-}
-
-
 Heap::RootListIndex Heap::RootIndexForEmptyFixedTypedArray(
     ElementsKind elementsKind) {
   switch (elementsKind) {
 #define ELEMENT_KIND_TO_ROOT_INDEX(Type, type, TYPE, ctype, size) \
   case TYPE##_ELEMENTS:                                           \
     return kEmptyFixed##Type##ArrayRootIndex;
 
     TYPED_ARRAYS(ELEMENT_KIND_TO_ROOT_INDEX)
 #undef ELEMENT_KIND_TO_ROOT_INDEX
     default:
       UNREACHABLE();
       return kUndefinedValueRootIndex;
   }
 }
 
 
-ExternalArray* Heap::EmptyExternalArrayForMap(Map* map) {
-  return ExternalArray::cast(
-      roots_[RootIndexForEmptyExternalArray(map->elements_kind())]);
-}
-
-
 FixedTypedArrayBase* Heap::EmptyFixedTypedArrayForMap(Map* map) {
   return FixedTypedArrayBase::cast(
       roots_[RootIndexForEmptyFixedTypedArray(map->elements_kind())]);
 }
 
 
 AllocationResult Heap::AllocateForeign(Address address,
                                        PretenureFlag pretenure) {
   // Statically ensure that it is safe to allocate foreigns in paged spaces.
   STATIC_ASSERT(Foreign::kSize <= Page::kMaxRegularHeapObjectSize);
@@ skipping 200 matching lines @@
 
   // Notify the heap profiler of change in object layout. The array may not be
   // moved during GC, and size has to be adjusted nevertheless.
   HeapProfiler* profiler = isolate()->heap_profiler();
   if (profiler->is_tracking_allocations()) {
     profiler->UpdateObjectSizeEvent(object->address(), object->Size());
   }
 }
 
 
-AllocationResult Heap::AllocateExternalArray(int length,
-                                             ExternalArrayType array_type,
-                                             void* external_pointer,
-                                             PretenureFlag pretenure) {
-  int size = ExternalArray::kSize;
+AllocationResult Heap::AllocateFixedTypedArrayWithExternalPointer(
+    int length, ExternalArrayType array_type, void* external_pointer,
+    PretenureFlag pretenure) {
+  int size = FixedTypedArrayBase::kHeaderSize;
   AllocationSpace space = SelectSpace(size, pretenure);
   HeapObject* result;
   {
     AllocationResult allocation = AllocateRaw(size, space, OLD_SPACE);
     if (!allocation.To(&result)) return allocation;
   }
 
-  result->set_map_no_write_barrier(MapForExternalArrayType(array_type));
-  ExternalArray::cast(result)->set_length(length);
-  ExternalArray::cast(result)->set_external_pointer(external_pointer);
-  return result;
+  result->set_map_no_write_barrier(MapForFixedTypedArray(array_type));
+  FixedTypedArrayBase* elements = FixedTypedArrayBase::cast(result);
+  elements->set_base_pointer(Smi::FromInt(0), SKIP_WRITE_BARRIER);
+  elements->set_external_pointer(external_pointer, SKIP_WRITE_BARRIER);
+  elements->set_length(length);
+  return elements;
 }
 
 static void ForFixedTypedArray(ExternalArrayType array_type, int* element_size,
                                ElementsKind* element_kind) {
   switch (array_type) {
 #define TYPED_ARRAY_CASE(Type, type, TYPE, ctype, size) \
   case kExternal##Type##Array:                          \
     *element_size = size;                               \
     *element_kind = TYPE##_ELEMENTS;                    \
     return;
@@ skipping 19 matching lines @@
   int size = OBJECT_POINTER_ALIGN(length * element_size +
                                   FixedTypedArrayBase::kDataOffset);
   AllocationSpace space = SelectSpace(size, pretenure);
 
   HeapObject* object;
   AllocationResult allocation = AllocateRaw(
       size, space, OLD_SPACE,
       array_type == kExternalFloat64Array ? kDoubleAligned : kWordAligned);
   if (!allocation.To(&object)) return allocation;
 
-  object->set_map(MapForFixedTypedArray(array_type));
+  object->set_map_no_write_barrier(MapForFixedTypedArray(array_type));
   FixedTypedArrayBase* elements = FixedTypedArrayBase::cast(object);
   elements->set_base_pointer(elements, SKIP_WRITE_BARRIER);
   elements->set_external_pointer(
       ExternalReference::fixed_typed_array_base_data_offset().address(),
       SKIP_WRITE_BARRIER);
   elements->set_length(length);
   if (initialize) memset(elements->DataPtr(), 0, elements->DataSize());
   return elements;
 }
 
@@ skipping 194 matching lines @@
 
   // Allocate the JSObject.
   int size = map->instance_size();
   AllocationSpace space = SelectSpace(size, pretenure);
   JSObject* js_obj;
   AllocationResult allocation = Allocate(map, space, allocation_site);
   if (!allocation.To(&js_obj)) return allocation;
 
   // Initialize the JSObject.
   InitializeJSObjectFromMap(js_obj, properties, map);
-  DCHECK(js_obj->HasFastElements() || js_obj->HasExternalArrayElements() ||
-         js_obj->HasFixedTypedArrayElements());
+  DCHECK(js_obj->HasFastElements() || js_obj->HasFixedTypedArrayElements());
   return js_obj;
 }
 
 
 AllocationResult Heap::AllocateJSObject(JSFunction* constructor,
                                         PretenureFlag pretenure,
                                         AllocationSite* allocation_site) {
   DCHECK(constructor->has_initial_map());
 
   // Allocate the object based on the constructors initial map.
@@ skipping 271 matching lines @@
     AllocationResult allocation = AllocateRaw(size, OLD_SPACE, OLD_SPACE);
     if (!allocation.To(&result)) return allocation;
   }
   // Initialize the object.
   result->set_map_no_write_barrier(fixed_array_map());
   FixedArray::cast(result)->set_length(0);
   return result;
 }
 
 
-AllocationResult Heap::AllocateEmptyExternalArray(
-    ExternalArrayType array_type) {
-  return AllocateExternalArray(0, array_type, NULL, TENURED);
-}
-
-
 AllocationResult Heap::CopyAndTenureFixedCOWArray(FixedArray* src) {
   if (!InNewSpace(src)) {
     return src;
   }
 
   int len = src->length();
   HeapObject* obj;
   {
     AllocationResult allocation = AllocateRawFixedArray(len, TENURED);
     if (!allocation.To(&obj)) return allocation;
@@ skipping 2402 matching lines @@
     *object_type = "CODE_TYPE";                                                \
     *object_sub_type = "CODE_AGE/" #name;                                      \
     return true;
     CODE_AGE_LIST_COMPLETE(COMPARE_AND_RETURN_NAME)
 #undef COMPARE_AND_RETURN_NAME
   }
   return false;
 }
 }  // namespace internal
 }  // namespace v8