Serious performance regression -- some tree optimizer questions

[Zdenek Dvorak]

Hello,

one more note:

> >  But by taking the optimizations into account at once,
> > you are able to get better results.
> 
> I'm pretty sure if we combined PRE, DCE, GVN, CCP, and everything else
> into hyper-global-mega-pass, we could get better results too :).

This analogy is obviously nonsense.  While the optimizations you mention
have very little in common, all the optimizations performed by ivopts
are of exactly the same type -- making an induction variable to be
expressed by a different biv.

Zdenek