g/ml/gcc-patches/2006-01/msg01851.html by Zdenek
> > which never made it to mainline.
> >
> > For constant loop count, ivcanon pass is adding reverse iv but this
> > not selected by ivopt.
>
> ivopt will never do loop reversal, if it would select this IV it would need t
ine.
>
> For constant loop count, ivcanon pass is adding reverse iv but this
> not selected by ivopt.
ivopt will never do loop reversal, if it would select this IV it would need to
keep the original one as well or compute the old i based on the new.
loop reversal needs dependence analysis and
I am looking into reversing loop to increased efficiency. There is
already a PR22041 for this and an old patch
https://gcc.gnu.org/ml/gcc-patches/2006-01/msg01851.html by Zdenek
which never made it to mainline.
For constant loop count, ivcanon pass is adding reverse iv but this
not selected by ivo
