for(t2 = 0; t2 <= an-1; t2++) {
  for(t4 = 0; t4 <= bm-1; t4++) {
    s0(t2,t4,0);
  }
}
for(t2 = 0; t2 <= an-1; t2++) {
  for(t4 = 0; t4 <= bm-1; t4++) {
    s2(t2,t4);
    for(t6 = 0; t6 <= -over1+ambn-1; t6 += 4) {
      s1(t2,t4,t6);
      s4(t2,t4,t6);
    }
    for(t6 = max(0,ambn-over1); t6 <= ambn-1; t6++) {
      s3(t2,t4,t6);
    }
  }
}