From 63c2f782e8f6aafbc11b14b2cb291b3dc9fc217d Mon Sep 17 00:00:00 2001 From: "Robert P. J. Day" Date: Tue, 30 Jan 2007 06:06:00 -0500 Subject: [POWERPC] Add "is_power_of_2" checking to log2.h. Add the inline function "is_power_of_2()" to log2.h, where the value zero is *not* considered to be a power of two. Signed-off-by: Robert P. J. Day Acked-by: Kumar Gala Signed-off-by: Paul Mackerras --- include/linux/log2.h | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'include') diff --git a/include/linux/log2.h b/include/linux/log2.h index d02e1a547a7..99922bedfcc 100644 --- a/include/linux/log2.h +++ b/include/linux/log2.h @@ -43,6 +43,17 @@ int __ilog2_u64(u64 n) } #endif +/* + * Determine whether some value is a power of two, where zero is + * *not* considered a power of two. + */ + +static inline __attribute__((const)) +bool is_power_of_2(unsigned long n) +{ + return (n != 0 && ((n & (n - 1)) == 0)); +} + /* * round up to nearest power of two */ -- cgit v1.2.3