My going to hell version:

https://github.com/rcs/fizzbuzz/blob/master/bitwise.c

Choice excerpts:

  char fmts[] = "FizzBuzz%u";

and

      // Default start is 8
    unsigned int start =
      // Shift down 1 if div5
      (8 >> DIV5(mask))
      // Shift down another 4 if div3 */
      >> ( DIV3(mask) << 2);