assertBitEquals(x, z);
          assertBitEquals(x - y, aa.get(i));
        }
      }
    }
  }

  /** updateAndGet adds given value to current, and returns current value */
  public void testUpdateAndGetWithSum() {
    AtomicDoubleArray aa = new AtomicDoubleArray(SIZE);
    for (int i : new int[] {0, SIZE - 1}) {
      for (double x : VALUES) {
        for (double y : VALUES) {
          aa.set(i, x);