gistfile1.cpp

uint32_t Djb2HashNoCase(const char *str_)
{
  const uint8_t *str = (const uint8_t *) str_;
	uint32_t hash      = 5381;
	int c;

	while (0 != (c = *str++))
	{
#if 1
    // Branch free case folding for ASCII
    const uint32_t cc           = uint32_t(c - 'A');
    const uint32_t is_upper     = -(cc <= ('Z' - 'A'));
    const uint32_t lower_case_c = c | 0x20;
    const uint32_t nocase_c     = (lower_case_c & is_upper) | (c & ~is_upper);
#else
    int nocase_c = (c >= 'A') && (c <= 'Z') ? c | 0x20 : c;
#endif
		hash = (hash * 33) + nocase_c;
	}

	return hash;
}