In-heap small typed arrays

src/heap.cc

 // 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 2917 matching lines @@
 
 #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
   }
   ASSERT(!InNewSpace(empty_fixed_array()));
   return true;
 }
 
 
 MaybeObject* Heap::AllocateHeapNumber(double value, PretenureFlag pretenure) {
   // Statically ensure that it is safe to allocate heap numbers in paged
   // spaces.
   int size = HeapNumber::kSize;
@@ skipping 813 matching lines @@
     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())]);
+}
+
+
 MaybeObject* Heap::NumberFromDouble(double value, PretenureFlag pretenure) {
   // We need to distinguish the minus zero value and this cannot be
   // done after conversion to int. Doing this by comparing bit
   // patterns is faster than using fpclassify() et al.
   if (IsMinusZero(value)) {
     return AllocateHeapNumber(-0.0, pretenure);
   }
 
   int int_value = FastD2I(value);
   if (value == int_value && Smi::IsValid(int_value)) {
@@ skipping 262 matching lines @@
   if (!maybe_object->To(&object)) return maybe_object;
 
   if (array_type == kExternalFloat64Array) {
     object = EnsureDoubleAligned(this, object, size);
   }
 
   FixedTypedArrayBase* elements =
       reinterpret_cast<FixedTypedArrayBase*>(object);
   elements->set_map(MapForFixedTypedArray(array_type));
   elements->set_length(length);
+  memset(elements->DataPtr(), 0, elements->DataSize());
   return elements;
 }
 
 
 MaybeObject* Heap::CreateCode(const CodeDesc& desc,
                               Code::Flags flags,
                               Handle<Object> self_reference,
                               bool immovable,
                               bool crankshafted,
                               int prologue_offset) {
@@ skipping 388 matching lines @@
   // Allocate the JSObject.
   int size = map->instance_size();
   AllocationSpace space = SelectSpace(size, OLD_POINTER_SPACE, pretenure);
   Object* obj;
   MaybeObject* maybe_obj = Allocate(map, space, allocation_site);
   if (!maybe_obj->To(&obj)) return maybe_obj;
 
   // Initialize the JSObject.
   InitializeJSObjectFromMap(JSObject::cast(obj), properties, map);
   ASSERT(JSObject::cast(obj)->HasFastElements() ||
-         JSObject::cast(obj)->HasExternalArrayElements());
+         JSObject::cast(obj)->HasExternalArrayElements() ||
+         JSObject::cast(obj)->HasFixedTypedArrayElements());
   return obj;
 }
 
 
 MaybeObject* Heap::AllocateJSObject(JSFunction* constructor,
                                     PretenureFlag pretenure,
                                     AllocationSite* allocation_site) {
   ASSERT(constructor->has_initial_map());
 
   // Allocate the object based on the constructors initial map.
@@ skipping 647 matching lines @@
   for (int i = 0; i < len; i++) result->set(i, src->get(i), mode);
 
   // TODO(mvstanton): The map is set twice because of protection against calling
   // set() on a COW FixedArray. Issue v8:3221 created to track this, and
   // we might then be able to remove this whole method.
   HeapObject::cast(obj)->set_map_no_write_barrier(fixed_cow_array_map());
   return result;
 }
 
 
+MaybeObject* Heap::AllocateEmptyFixedTypedArray(ExternalArrayType array_type) {
+  return AllocateFixedTypedArray(0, array_type, TENURED);
+}
+
+
 MaybeObject* Heap::CopyFixedArrayWithMap(FixedArray* src, Map* map) {
   int len = src->length();
   Object* obj;
   { MaybeObject* maybe_obj = AllocateRawFixedArray(len, NOT_TENURED);
     if (!maybe_obj->ToObject(&obj)) return maybe_obj;
   }
   if (InNewSpace(obj)) {
     HeapObject* dst = HeapObject::cast(obj);
     dst->set_map_no_write_barrier(map);
     CopyBlock(dst->address() + kPointerSize,
@@ skipping 2664 matching lines @@
       static_cast<int>(object_sizes_last_time_[index]));
   CODE_AGE_LIST_COMPLETE(ADJUST_LAST_TIME_OBJECT_COUNT)
 #undef ADJUST_LAST_TIME_OBJECT_COUNT
 
   OS::MemCopy(object_counts_last_time_, object_counts_, sizeof(object_counts_));
   OS::MemCopy(object_sizes_last_time_, object_sizes_, sizeof(object_sizes_));
   ClearObjectStats();
 }
 
 } }  // namespace v8::internal