Re: Improvements of the haifa scheduler

["Daniel Berlin" <dberlin at dberlin dot org>]

On 3/5/07, Maxim Kuvyrkov <mkuvyrkov@ispras.ru> wrote:
> Diego Novillo wrote:
> > Maxim Kuvyrkov wrote on 03/05/07 02:14:
> >
> >>    o Fix passes that invalidate tree-ssa alias export.
> >
> > Yes, this should be good and shouldn't need a lot of work.
> >
> >>    o { Fast but unsafe Gupta's aliasing patch, Unsafe tree-ssa alias
> >> export } in scheduler's data speculation.
> >
> > "unsafe" alias export?  I would definitely like to see the tree->rtl
> > alias information transfer fixed once and for all.  Finishing RAS's
> > tree->rtl work would probably make a good SoC project.
>
> "Unsafe" doesn't mean not fixed.  My thought is that it would be nice to
> have a switch in aliasing that will turn such operations as
>
> join (pt_anything, points_to) -> pt_anything
>
> into
>
> join (pt_anything, points_to) -> points_to
>
> This transformation will sacrifice correctness for sake of additional
> information.

In 4.3, doesn't exist outside of the confines of tree-ssa-structalias.c
We transform it into a conservatively correct set of variables, rather
than giving up like we used to.

This alone should significantly improve your export results.