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| author | Chunyan Zhang <chunyan.zhang@unisoc.com> | 2020-07-24 20:21:47 +0800 |
|---|---|---|
| committer | Sebastian Reichel <sebastian.reichel@collabora.com> | 2020-07-28 00:47:18 +0200 |
| commit | af60459a543483c5ad155a92daa8c3a6c00a0829 (patch) | |
| tree | 7c38ee31d9ee6f37e750033a6df3ca2094ff7187 | |
| parent | ab92ffd5f6ac3ebd4a7650ef906702ab86127b45 (diff) | |
| download | lwn-af60459a543483c5ad155a92daa8c3a6c00a0829.tar.gz lwn-af60459a543483c5ad155a92daa8c3a6c00a0829.zip | |
math64: New DIV_S64_ROUND_CLOSEST helper
Provide DIV_S64_ROUND_CLOSEST helper which uses div_s64 to perform
division rounded to the closest integer using signed 64bit
dividend and signed 32bit divisor.
Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
| -rw-r--r-- | include/linux/math64.h | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/include/linux/math64.h b/include/linux/math64.h index 11a267413e8e..cd0693989436 100644 --- a/include/linux/math64.h +++ b/include/linux/math64.h @@ -279,4 +279,23 @@ static inline u64 mul_u64_u32_div(u64 a, u32 mul, u32 divisor) #define DIV64_U64_ROUND_CLOSEST(dividend, divisor) \ ({ u64 _tmp = (divisor); div64_u64((dividend) + _tmp / 2, _tmp); }) +/* + * DIV_S64_ROUND_CLOSEST - signed 64bit divide with 32bit divisor rounded to nearest integer + * @dividend: signed 64bit dividend + * @divisor: signed 32bit divisor + * + * Divide signed 64bit dividend by signed 32bit divisor + * and round to closest integer. + * + * Return: dividend / divisor rounded to nearest integer + */ +#define DIV_S64_ROUND_CLOSEST(dividend, divisor)( \ +{ \ + s64 __x = (dividend); \ + s32 __d = (divisor); \ + ((__x > 0) == (__d > 0)) ? \ + div_s64((__x + (__d / 2)), __d) : \ + div_s64((__x - (__d / 2)), __d); \ +} \ +) #endif /* _LINUX_MATH64_H */ |