On Mon, 2015-02-02 at 09:12 -0800, Anshul Garg wrote:
> From: Anshul Garg <aksgarg1...@gmail.com>
>
> Unnecessary instructions are executing even though m is
> greater than x so added logic to make m less than equal to
> x before performing these operations.
>
> Signed-off-by: Anshul Garg <aksgarg1...@gmail.com>
> ---
> lib/int_sqrt.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/lib/int_sqrt.c b/lib/int_sqrt.c
[]
> @@ -22,6 +22,9 @@ unsigned long int_sqrt(unsigned long x)
> return x;
>
> m = 1UL << (BITS_PER_LONG - 2);
> +
> + while (m > x)
> + m >>= 2;
Perhaps removing the while and using fls(x) would be better.
Perhaps something like:
m = 1UL << min(sizeof(unsigned long) == sizeof(u64) ?
fls64(x) : fls(x),
BITS_PER_LONG - 2);
> while (m != 0) {
> b = y + m;
> y >>= 1;
--
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