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From: Alex Williamson <alex.williamson@redhat.com>
Date: Fri, 16 Aug 2013 09:46:42 -0600
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Subject: Re: [Qemu-devel] [PATCH v2] exec: Fix non-power-of-2 sized accesses
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To: Richard Henderson <rth@twiddle.net>
Cc: lersek@redhat.com, qemu-devel@nongnu.org, qemu-stable@nongnu.org

On Fri, 2013-08-16 at 09:43 -0600, Alex Williamson wrote:
> On Fri, 2013-08-16 at 09:37 -0600, Alex Williamson wrote:
> > On Fri, 2013-08-16 at 08:27 -0700, Richard Henderson wrote:
> > > On 08/16/2013 05:50 AM, Alex Williamson wrote:
> > > > +    /* Size must be a power of 2 */
> > > > +    if (l & (l - 1)) {
> > > > +        while (l & (access_size_max - 1)) {
> > > > +            access_size_max >>= 1;
> > > > +        }
> > > > +    }
> > > > +
> > > 
> > > Why the loop at all?  x & -x extracts the lsb of x.
> > 
> > l = 5, we want 4, not 1.  Thanks,
> 
> Which is not what my patch does either :-\

Simple change though

  while (!(l & access_size_max))...