Faster filling of arrays of holes.

src/heap.cc

 // Copyright 2009 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 2960 matching lines @@
 
 Object* Heap::AllocateFixedArrayWithHoles(int length) {
   if (length == 0) return empty_fixed_array();
   Object* result = AllocateRawFixedArray(length);
   if (!result->IsFailure()) {
     // Initialize header.
     reinterpret_cast<Array*>(result)->set_map(fixed_array_map());
     FixedArray* array = FixedArray::cast(result);
     array->set_length(length);
     // Initialize body.
-    Object* value = the_hole_value();
-    for (int index = 0; index < length; index++)  {
-      ASSERT(!Heap::InNewSpace(value));  // value = the hole
-      array->set(index, value, SKIP_WRITE_BARRIER);
-    }
+    ASSERT(!Heap::InNewSpace(the_hole_value()));
+    MemsetPointer(HeapObject::RawField(array, FixedArray::kHeaderSize),
+                  the_hole_value(),
+                  length);
   }
   return result;
 }
 
 
 Object* Heap::AllocateHashTable(int length) {
   Object* result = Heap::AllocateFixedArray(length);
   if (result->IsFailure()) return result;
   reinterpret_cast<Array*>(result)->set_map(hash_table_map());
   ASSERT(result->IsHashTable());
@@ skipping 1223 matching lines @@
 void ExternalStringTable::TearDown() {
   new_space_strings_.Free();
   old_space_strings_.Free();
 }
 
 
 List<Object*> ExternalStringTable::new_space_strings_;
 List<Object*> ExternalStringTable::old_space_strings_;
 
 } }  // namespace v8::internal