Messages in this thread Patch in this message | | | From | Lai Jiangshan <> | Subject | [RFC PATCH 1/6] kenrel.h: add ALIGN_OF_LAST_BIT() | Date | Tue, 20 Mar 2012 18:21:19 +0800 |
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Get the biggest 2**y that x % (2**y) == 0 for the align value.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> --- include/linux/kernel.h | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-)
diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 5113462..2c439dc 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -44,6 +44,8 @@ #define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a))) #define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0) +#define ALIGN_OF_LAST_BIT(x) ((((x)^((x) - 1))>>1) + 1) + #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr)) /* -- 1.7.4.4
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