int swapElements(int a[], int i, int j)
{
  int tmp;
  tmp = a[i];
  a[i] = a[j];
  a[j] = tmp;
}

   

The compiler decides to generate code something like this with 4 assignments instead of 3:

      int tmp1, tmp2;
      tmp1 = a[i];
      tmp2 = a[j];
      a[i] = tmp2;
      a[j] = tmp1;