Recognize _TypedListBase._cid native. Use Lists.copy instead of native _setRange if list is small. …

runtime/lib/typed_data.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 // patch classes for Int8List ..... Float64List and ByteData implementations.
 
 import "dart:_internal";
 import 'dart:math' show Random;
 
 patch class Int8List {
@@ skipping 530 matching lines @@
       throw new ArgumentError(skipCount);
     }
 
     final count = end - start;
     if ((from.length - skipCount) < count) {
       throw new StateError("Not enough elements");
     }
 
     if (from is _TypedListBase) {
       if (this.elementSizeInBytes == from.elementSizeInBytes) {
-        if (this.buffer._setRange(
+        if ((count < 10) && (from.buffer != this.buffer)) {
+          Lists.copy(from, skipCount, this, start, count);
+          return;
+        } else if (this.buffer._setRange(
               start * elementSizeInBytes + this.offsetInBytes,
               count * elementSizeInBytes,
               from.buffer,
               skipCount * elementSizeInBytes + from.offsetInBytes,
               this._cid, from._cid)) {
           return;
         }
       } else if (from.buffer == this.buffer) {
         // Different element sizes, but same buffer means that we need
         // an intermediate structure.
@@ skipping 3069 matching lines @@
     return value;
   }
   return object;
 }
 
 
 void _throwRangeError(int index, int length) {
   String message = "$index must be in the range [0..$length)";
   throw new RangeError(message);
 }