From: Chris Metcalf Date: Fri, 25 May 2012 16:32:09 +0000 (-0400) Subject: tile: fix bug where fls(0) was not returning 0 X-Git-Tag: v3.5-rc1~76^2~1 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=9f1d62bed7f015d11b9164078b7fea433b474114;p=platform%2Fkernel%2Flinux-exynos.git tile: fix bug where fls(0) was not returning 0 This is because __builtin_clz(0) returns 64 for the "undefined" case of 0, since the builtin just does a right-shift 32 and "clz" instruction. So, use the alpha approach of casting to u32 and using __builtin_clzll(). Cc: stable@vger.kernel.org Signed-off-by: Chris Metcalf --- diff --git a/arch/tile/include/asm/bitops.h b/arch/tile/include/asm/bitops.h index 16f1fa5..bd186c4 100644 --- a/arch/tile/include/asm/bitops.h +++ b/arch/tile/include/asm/bitops.h @@ -77,6 +77,11 @@ static inline int ffs(int x) return __builtin_ffs(x); } +static inline int fls64(__u64 w) +{ + return (sizeof(__u64) * 8) - __builtin_clzll(w); +} + /** * fls - find last set bit in word * @x: the word to search @@ -90,12 +95,7 @@ static inline int ffs(int x) */ static inline int fls(int x) { - return (sizeof(int) * 8) - __builtin_clz(x); -} - -static inline int fls64(__u64 w) -{ - return (sizeof(__u64) * 8) - __builtin_clzll(w); + return fls64((unsigned int) x); } static inline unsigned int __arch_hweight32(unsigned int w)