#define FIZZ 1
  #define BUZZ 2
  static const uint8_t divs[] = 
 {FIZZ+BUZZ,0,0,FIZZ,0,BUZZ,FIZZ,0,0,FIZZ,BUZZ,0,FIZZ,0,0};
  static const char* strs[] = {
    [0] = "%u\n",
    [FIZZ] = "fizz\n",
    [BUZZ] = "buzz\n",
    [FIZZ+BUZZ] = "fizzbuzz\n"
  };

  void fizzbuzz(uint32_t upTo)
  {
    uint32_t i, state;

    for(i = state = 0; i < upTo; i++) {
      printf(strs[divs[state]], i);
      if(++state == sizeof(divs) / sizeof(*divs))
          state = 0;
  }

No divisibility tests at all

One level of arrays may be skipped at cost of extra .rodata size (store string pointers directly in divs). But in a modern cpu cost of the extra load is small