Re: [ros-dev] [ros-diffs] [tkreuzer] 44464: [RTL] Rewrite the rtl bitmap implementation. The old one was a little .... suboptimal. The new one should outperform the old one by several orders of magnitude, especially RtlFindClearBits that was literally searching bit by bit.

[Alex Ionescu]

So? Use intrinsics anyways.

Or __builtin_clz...

On 2009-12-07, at 10:07 PM, Timo Kreuzer wrote:
> Because this is a host module.
>
> Alex Ionescu wrote:
> > Well why this then? They should be intrinsics...
> >
> > On 2009-12-07, at 8:43 PM, Timo Kreuzer wrote:
> > > > > +unsigned char BitScanForward(ULONG * Index, unsigned long Mask)
> > > > > +{
> > > > > *Index = 0;
> > > > > while (Mask && ((Mask & 1) == 0))
> > > > > {
> > > > >    Mask >>= 1;
> > > > >    ++(*Index);
> > > > > }
> > > > > return Mask ? 1 : 0;
> > > > >
> > > > > +}
> > > > >
> > > > > +unsigned char BitScanReverse(ULONG * const Index, unsigned long Mask)
> > > > > +{
> > > > > *Index = 0;
> > > > > while (Mask && ((Mask & (1 << 31)) == 0))
> > > > > {
> > > > >    Mask <<= 1;
> > > > >    ++(*Index);
> > > > > }
> > > > > return Mask ? 1 : 0;
> > > > >
> > > > > +}
> >
> > Best regards,
> > Alex Ionescu
> >
> > Ros-dev mailing list
> > [e-mail]
> > http://www.reactos.org/mailman/listinfo/ros-dev
>
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Best regards,
Alex Ionescu