- Optimized CopyFixedArray and CopyJSObject.

src/heap-inl.h

 // Copyright 2006-2008 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 128 matching lines @@
   InstanceType type = object->map()->instance_type();
   ASSERT((type != CODE_TYPE) && (type != MAP_TYPE));
   bool has_pointers =
       type != HEAP_NUMBER_TYPE &&
       (type >= FIRST_NONSTRING_TYPE ||
        String::cast(object)->representation_tag() != kSeqStringTag);
   return has_pointers ? old_pointer_space_ : old_data_space_;
 }
 
 
+void Heap::CopyBlock(Object** dst, Object** src, int byte_size) {
+  ASSERT(IsAligned(byte_size, kPointerSize));
+
+  // Use block copying memcpy if the segment we're copying is
+  // enough to justify the extra call/setup overhead.
+  static const int kBlockCopyLimit = 16 * kPointerSize;
+
+  if (byte_size >= kBlockCopyLimit) {
+    memcpy(dst, src, byte_size);
+  } else {
+    int remaining = byte_size / kPointerSize;
+    do {
+      remaining--;
+      *dst++ = *src++;
+    } while (remaining > 0);
+  }
+}
+
+
 #define GC_GREEDY_CHECK() \
   ASSERT(!FLAG_gc_greedy || v8::internal::Heap::GarbageCollectionGreedyCheck())
 
 // Do not use the identifier __object__ in a call to this macro.
 //
 // Call the function FUNCTION_CALL.  If it fails with a RetryAfterGC
 // failure, call the garbage collector and retry the function.  If the
 // garbage collector cannot reclaim the required space or the second
 // call fails with a RetryAfterGC failure, fail with out of memory.
 // If there is any other failure, return a null handle.  If either
@@ skipping 67 matching lines @@
   allocation_allowed_ = new_state;
   return old;
 }
 
 #endif
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_INL_H_