From d57594c203b1e7b54373080a797f0cbfa4aade68 Mon Sep 17 00:00:00 2001 From: Alexander van Heukelum Date: Sat, 15 Mar 2008 18:32:36 +0100 Subject: bitops: use __fls for fls64 on 64-bit archs Use __fls for fls64 on 64-bit archs. The implementation for 64-bit archs is moved from x86_64 to asm-generic. Signed-off-by: Alexander van Heukelum Signed-off-by: Ingo Molnar --- include/asm-generic/bitops/fls64.h | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) (limited to 'include/asm-generic/bitops') diff --git a/include/asm-generic/bitops/fls64.h b/include/asm-generic/bitops/fls64.h index 1b6b17ce242..86d403f8b25 100644 --- a/include/asm-generic/bitops/fls64.h +++ b/include/asm-generic/bitops/fls64.h @@ -3,6 +3,18 @@ #include +/** + * 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; @@ -10,5 +22,15 @@ static inline int fls64(__u64 x) 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_ */ -- cgit v1.2.3