Also allocate small typed arrays on heap when initialized from an array-like

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 3712 matching lines @@
     default:
       *element_size = 0;               // Bogus
       *element_kind = UINT8_ELEMENTS;  // Bogus
       UNREACHABLE();
   }
 }
 
 
 AllocationResult Heap::AllocateFixedTypedArray(int length,
                                                ExternalArrayType array_type,
+                                               bool initialize,
                                                PretenureFlag pretenure) {
   int element_size;
   ElementsKind elements_kind;
   ForFixedTypedArray(array_type, &element_size, &elements_kind);
   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));
   FixedTypedArrayBase* elements = FixedTypedArrayBase::cast(object);
   elements->set_length(length);
-  memset(elements->DataPtr(), 0, elements->DataSize());
+  if (initialize) memset(elements->DataPtr(), 0, elements->DataSize());
   return elements;
 }
 
 
 AllocationResult Heap::AllocateCode(int object_size, bool immovable) {
   DCHECK(IsAligned(static_cast<intptr_t>(object_size), kCodeAlignment));
   AllocationResult allocation =
       AllocateRaw(object_size, CODE_SPACE, CODE_SPACE);
 
   HeapObject* result;
@@ skipping 549 matching lines @@
   // 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;
 }
 
 
 AllocationResult Heap::AllocateEmptyFixedTypedArray(
     ExternalArrayType array_type) {
-  return AllocateFixedTypedArray(0, array_type, TENURED);
+  return AllocateFixedTypedArray(0, array_type, false, TENURED);
 }
 
 
 AllocationResult Heap::CopyFixedArrayWithMap(FixedArray* src, Map* map) {
   int len = src->length();
   HeapObject* obj;
   {
     AllocationResult allocation = AllocateRawFixedArray(len, NOT_TENURED);
     if (!allocation.To(&obj)) return allocation;
   }
@@ skipping 2334 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 v8::internal