1for (int c0 = 2; c0 < n - 1; c0 += 4) {
2 s1(c0);
3 s0(c0 + 2);
4}
5if (n >= 1 && n % 4 >= 2)
6 s1(-(n % 4) + n + 2);
7

source code of polly/lib/External/isl/test_inputs/codegen/pldi2012/figure8_b.c