Messages in this thread | | | From | Andy Shevchenko <> | Date | Mon, 19 Jul 2021 15:47:07 +0300 | Subject | Re: [PATCH v3 1/5] math64: New DIV_U64_ROUND_CLOSEST helper |
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On Sat, Jul 17, 2021 at 3:39 PM Pali Rohár <pali@kernel.org> wrote: > > Provide DIV_U64_ROUND_CLOSEST helper which uses div_u64 to perform > division rounded to the closest integer using unsigned 64bit > dividend and unsigned 32bit divisor.
...
> +/* > + * DIV_U64_ROUND_CLOSEST - unsigned 64bit divide with 32bit divisor rounded to nearest integer
> + * @dividend: unsigned 64bit dividend
Here you insist users to provide a u64 (or compatible) type.
> + * @divisor: unsigned 32bit divisor > + * > + * Divide unsigned 64bit dividend by unsigned 32bit divisor > + * and round to closest integer. > + * > + * Return: dividend / divisor rounded to nearest integer > + */ > +#define DIV_U64_ROUND_CLOSEST(dividend, divisor) \
> + ({ u32 _tmp = (divisor); div_u64((u64)(dividend) + _tmp / 2, _tmp); })
Here is the casting to u64. Why? (Yes, I have read v1 discussion and I just want to continue it here).
-- With Best Regards, Andy Shevchenko
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