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Fabio Estevam77c85542015-11-05 12:43:23 -02001#ifndef _ASM_GENERIC_BITOPS_FLS64_H_
2#define _ASM_GENERIC_BITOPS_FLS64_H_
3
4#include <asm/types.h>
5
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
18static __always_inline int fls64(__u64 x)
19{
20 __u32 h = x >> 32;
21 if (h)
22 return fls(h) + 32;
23 return fls(x);
24}
25#elif BITS_PER_LONG == 64
26static __always_inline int fls64(__u64 x)
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
35
36#endif /* _ASM_GENERIC_BITOPS_FLS64_H_ */