[cairo] Re: Some other bits...

[Behdad Esfahbod]

On Thu, 18 Aug 2005, Bertram Felgenhauer wrote:

> On 8/18/05, Behdad Esfahbod <behdad at cs.toronto.edu> wrote:
> > > There's a standard trick for this, though.  If you want to guarantee
> > > arithmetic (signed) right shift, you can say:
> > >
> > > 	a = (b >> shift) | ~(-1 >> shift);
> >
> > Then you fall into another hole:  it assumes 2-complete arithmetic ;).
>
> 2's complement, I think.

Oops.  I knew it's time to go to sleep. (and still is)


> But it does not even work; the top bits are also added if b is positive,
> giving an incorrect result.

Ah, right.  I was too amused by it.


> Bertram

--behdad
http://behdad.org/