Re: [RFC][PATCH] Faster generic_fls

Linus Torvalds (torvalds@transmeta.com)
Wed, 30 Apr 2003 16:41:07 -0700 (PDT)

On 30 Apr 2003, Alan Cox wrote:
>
> It ought to be basically the same as ffs because if I remember rightly
>
> ffs(x^(x-1)) == fls(x)

So did anybody time this? ffs() we have hardware support for on x86, and
it's even reasonably efficient on some CPU's .. So this _should_ beat all
new-comers, and obviously some people already have benchmark programs
ready and willing..

Linus

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