[fio.git] / lib / ffz.h

#ifndef FIO_FFZ_H
#define FIO_FFZ_H

#include <inttypes.h>

static inline int ffs64(uint64_t word)
{
	int r = 0;

	if ((word & 0xffffffff) == 0) {
		r += 32;
		word >>= 32;
	}
	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))
		r += 1;

	return r;
}

#ifndef ARCH_HAVE_FFZ

static inline int ffz(unsigned long bitmask)
{
	return ffs64(~bitmask);
}

#else
#define ffz(bitmask)	arch_ffz(bitmask)
#endif

static inline int ffz64(uint64_t bitmask)
{
	return ffs64(~bitmask);
}

#endif
Commit	Line	Data
064c636d JA	1	#ifndef FIO_FFZ_H
	2	#define FIO_FFZ_H
	3
f8582257 JA	4	#include <inttypes.h>
	5
	6	static inline int ffs64(uint64_t word)
064c636d	7	{
09174445	8	int r = 0;
064c636d	9
0ce8b119 JA	10	if ((word & 0xffffffff) == 0) {
	11	r += 32;
	12	word >>= 32;
	13	}
064c636d JA	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	}
034ada86	30	if (!(word & 1))
064c636d	31	r += 1;
064c636d JA	32
	33	return r;
	34	}
	35
f8582257 JA	36	#ifndef ARCH_HAVE_FFZ
f8582257 JA	37
0ce8b119	38	static inline int ffz(unsigned long bitmask)
064c636d	39	{
f8582257 JA	40	return ffs64(~bitmask);
	41	}
	42
	43	#else
	44	#define ffz(bitmask) arch_ffz(bitmask)
	45	#endif
	46
	47	static inline int ffz64(uint64_t bitmask)
	48	{
	49	return ffs64(~bitmask);
064c636d JA	50	}
	51
	52	#endif