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SubjectRe: [PATCH] tcp_cubic: use 32 bit math
David Miller wrote:
> From: Stephen Hemminger <shemminger@linux-foundation.org>
> Date: Wed, 7 Mar 2007 17:07:31 -0800
>
>
>> The basic calculation has to be done in 32 bits to avoid
>> doing 64 bit divide by 3. The value x is only 22bits max
>> so only need full 64 bits only for x^2.
>>
>> Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
>>
>
> Applied, thanks Stephen.
>
> What about Willy Tarreau's supposedly even faster variant?
> Or does this incorporate that set of improvements?
>
That's what this is:
x = (2 * x + (uint32_t)div64_64(a, (uint64_t)x*(uint64_t)x)) / 3;

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