Re: [PATCH] lib/int_sqrt.c: Optimize square root function

[Peter Zijlstra]

On Thu, Jul 20, 2017 at 04:52:49AM -0700, Joe Perches wrote:
> On Thu, 2017-07-20 at 13:24 +0200, Peter Zijlstra wrote:
> []
> > +   m = 1UL << ((fls(x) + 1) & ~1UL);
> 
> maybe 
> 
> #if BITS_PER_LONG == 64
>       m = 1UL << ((fls64(x) + 1) & ~1UL);
> #else
>       m = 1UL << ((fls(x) + 1) & ~1UL);
> #endif

We do seem to have __fls() which is defined on long.