[fio.git] / lib / ffz.h

#ifndef FIO_FFZ_H
#define FIO_FFZ_H

static inline int __ffs(unsigned long word)
{
	int r = 0;

#if BITS_PER_LONG == 64
	if ((word & 0xffffffff) == 0) {
		r += 32;
		word >>= 32;
	}
#endif
	if (!(word & 0xffff)) {
		word >>= 16;
		r += 16;
	}
	if (!(word & 0xff)) {
		word >>= 8;
		r += 8;
	}
	if (!(word & 0xf)) {
		word >>= 4;
		r += 4;
	}
	if (!(word & 3)) {
		word >>= 2;
		r += 2;
	}
	if (!(word & 1)) {
		word >>= 1;
		r += 1;
	}

	return r;
}

static inline int ffz(unsigned long bitmask)
{
	return __ffs(~bitmask);
}

#endif
Commit	Line	Data
	1	#ifndef FIO_FFZ_H
	2	#define FIO_FFZ_H
	3
	4	static inline int __ffs(unsigned long word)
	5	{
	6	int r = 0;
	7
	8	#if BITS_PER_LONG == 64
	9	if ((word & 0xffffffff) == 0) {
	10	r += 32;
	11	word >>= 32;
	12	}
	13	#endif
	14	if (!(word & 0xffff)) {
	15	word >>= 16;
	16	r += 16;
	17	}
	18	if (!(word & 0xff)) {
	19	word >>= 8;
	20	r += 8;
	21	}
	22	if (!(word & 0xf)) {
	23	word >>= 4;
	24	r += 4;
	25	}
	26	if (!(word & 3)) {
	27	word >>= 2;
	28	r += 2;
	29	}
	30	if (!(word & 1)) {
	31	word >>= 1;
	32	r += 1;
	33	}
	34
	35	return r;
	36	}
	37
	38	static inline int ffz(unsigned long bitmask)
	39	{
	40	return __ffs(~bitmask);
	41	}
	42
	43	#endif