On Mon, Dec 18, 2017 at 04:05:44PM +0100, Crt Mori wrote:
> There is no option to perform 64bit integer sqrt on 32bit platform.
> Added stronger typed int_sqrt64 enables the 64bit calculations to
> be performed on 32bit platforms. Although int_sqrt() is a rough
> approximation, the same algorithm is used in int_sqrt64() as good
> enough on 32bit platform.
You clearly haven't read a recent version of the file you're patching.
Please take a moment to do so now.
> +/**
> + * int_sqrt64 - strongly typed int_sqrt function
> + * @x: 64bit integer of which to calculate the sqrt
> + */
> +u64 int_sqrt64(u64 x)
Please explain how the result of sqrt(u64) can be larger than u32.
Also, I expect that this fact could be exploited to optimize this for
32bit archs if one were so inclined.
> +{
> + u64 b, m, y = 0;
> +
> + if (x <= 1)
> + return x;
> +
> + m = 1ULL << (64 - 2);
> + while (m != 0) {
> + b = y + m;
> + y >>= 1;
> +
> + if (x >= b) {
> + x -= b;
> + y += m;
> + }
> + m >>= 2;
> + }
> + return y;
> +}
so yeah, no, please try again after reading the current file.
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