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
> >  
> >  
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> >  
> >   
>  
>  
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Best regards,
Alex Ionescu