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| File: [Development] / linux-2.6-xfs / include / asm-generic / bitops / fls64.h (download)
Revision 1.2, Mon Aug 4 17:03:13 2008 UTC (9 years, 2 months ago) by lachlan.longdrop.melbourne.sgi.com
Merge up to 2.6.26 Merge of 2.6.x-xfs-melb:linux:31804b by kenmcd. |
#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 inline int fls64(__u64 x)
{
__u32 h = x >> 32;
if (h)
return fls(h) + 32;
return fls(x);
}
#elif BITS_PER_LONG == 64
static 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_ */