RE: [PATCH 0/10] use safer test on the result of find_first_zero_bit

From: David Laight
Date: Wed Jun 04 2014 - 05:46:51 EST


From: Julia Lawall
> On Wed, 4 Jun 2014, Geert Uytterhoeven wrote:
>
> > Hi Julia,
> >
> > On Wed, Jun 4, 2014 at 11:07 AM, Julia Lawall <Julia.Lawall@xxxxxxx> wrote:
> > > Find_first_zero_bit considers BITS_PER_LONG bits at a time, and thus may
> > > return a larger number than the maximum position argument if that position
> > > is not a multiple of BITS_PER_LONG.
> >
> > Shouldn't this be fixed in find_first_zero_bit() instead?
>
> OK, I could do that as well. Most of the callers currently test with >=.
> Should they be left as is, or changed to use ==?

Do we want to add an extra test to find_first_zero_bit() and effectively
slow down all the calls - especially those where the length is a
multiple of 8 (probably the most common).

Maybe the documented return code should be changed to allow for the
existing behaviour.

David



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