[deliverable/linux.git] / include / asm-generic / bitops / fls64.h

#ifndef _ASM_GENERIC_BITOPS_FLS64_H_
#define _ASM_GENERIC_BITOPS_FLS64_H_

#include <asm/types.h>

/**
 * fls64 - find last set bit in a 64-bit word
 * @x: the word to search
 *
 * This is defined in a similar way as the libc and compiler builtin
 * ffsll, but returns the position of the most significant set bit.
 *
 * fls64(value) returns 0 if value is 0 or the position of the last
 * set bit if value is nonzero. The last (most significant) bit is
 * at position 64.
 */
#if BITS_PER_LONG == 32
static __always_inline int fls64(__u64 x)
{
	__u32 h = x >> 32;
	if (h)
		return fls(h) + 32;
	return fls(x);
}
#elif BITS_PER_LONG == 64
static __always_inline int fls64(__u64 x)
{
	if (x == 0)
		return 0;
	return __fls(x) + 1;
}
#else
#error BITS_PER_LONG not 32 or 64
#endif

#endif /* _ASM_GENERIC_BITOPS_FLS64_H_ */
Commit	Line	Data
2dfc383a AM	1	#ifndef _ASM_GENERIC_BITOPS_FLS64_H_
	2	#define _ASM_GENERIC_BITOPS_FLS64_H_
	3
a54baa14 AM	4	#include <asm/types.h>
a54baa14 AM	5
d57594c2 AH	6	/**
	7	* fls64 - find last set bit in a 64-bit word
	8	* @x: the word to search
	9	*
	10	* This is defined in a similar way as the libc and compiler builtin
	11	* ffsll, but returns the position of the most significant set bit.
	12	*
	13	* fls64(value) returns 0 if value is 0 or the position of the last
	14	* set bit if value is nonzero. The last (most significant) bit is
	15	* at position 64.
	16	*/
	17	#if BITS_PER_LONG == 32
c8399943	18	static __always_inline int fls64(__u64 x)
2dfc383a AM	19	{
	20	__u32 h = x >> 32;
	21	if (h)
	22	return fls(h) + 32;
	23	return fls(x);
	24	}
d57594c2	25	#elif BITS_PER_LONG == 64
c8399943	26	static __always_inline int fls64(__u64 x)
d57594c2 AH	27	{
	28	if (x == 0)
	29	return 0;
	30	return __fls(x) + 1;
	31	}
	32	#else
	33	#error BITS_PER_LONG not 32 or 64
	34	#endif
2dfc383a AM	35
2dfc383a AM	36	#endif /* _ASM_GENERIC_BITOPS_FLS64_H_ */