codegen/cloog/forwardsub-2-1-2-3.c

S3(1, 0);
for (int c2 = 2; c2 <= M; c2 += 1)
  S1(1, 1, c2);
for (int c0 = 2; c0 <= M; c0 += 1) {
  S4(c0, 0);
  for (int c2 = c0 + 1; c2 <= M; c2 += 1)
    S2(c0, 1, c2);
}