_ f(int a, int b, int c, int d, int e, int f, int g, int h, int i, int j, int k) {
  return (h, e, d, j, k, f, i, a, b, c, g);   ;; optimal code is 3 ops, 6 bytes
  ;; s3 s10 XCHG  s6 s7 s6 XCHG3  s9 s8 s4 XCHG3
}