asm("bsr %1,%0"

#if defined(__GNUC__) && ((__GNUC__ * 100 + __GNUC_MINOR__) >= 304)

	    : "=r" (word)

	return word == 0 ? 0 : 32 - __builtin_clz(word);

	    : "rm" (word));

#else

	return word;

	unsigned int v = 1;

	if (word == 0)

		return 0;

	while (word >>= 1)

		v++;

	return v;

#endif