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Re: Use assert()s for optimization?


On Friday 7 November 2003 11:01, Falk Hueffner wrote:
> Richard Guenther <rguenth@tat.physik.uni-tuebingen.de> writes:
> > Is there a way to turn an assert() into optimization hints for gcc?
> > Like in
> >
> > double mysqrt(double x)
> > {
> >   assert(x >= 0.0);
> >   return sqrt(x);
> > }
>
> Interestingly, Toon Moene just asked for the same thing on
> gcc-patches :) I don't think it's currently possible. Maybe we could
> have
> something similar to Microsoft's __assume(), which would then feed
> the nonnegative_p etc. functions and the VRP to come. I'm not sure
> how to represent it best in the intermediary representation, though.

Doesn't __builtin_expect() already do this?

-- 
Ross Smith ......... r-smith@ihug.co.nz ......... Auckland, New Zealand
  "The vast majority of Iraqis want to live in a peaceful, free world.
  And we will find these people and we will bring them to justice."
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