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Re: Loop optimizer issues
- From: <tm_gccmail at mail dot kloo dot net>
- To: Zdenek Dvorak <rakdver at atrey dot karlin dot mff dot cuni dot cz>
- Cc: Diego Novillo <dnovillo at redhat dot com>,"gcc at gcc dot gnu dot org" <gcc at gcc dot gnu dot org>,Richard Henderson <rth at redhat dot com>, Jason Merrill <jason at redhat dot com>,pop at gauvain dot u-strasbg dot fr, Jan Hubicka <jh at suse dot cz>,Daniel Berlin <dberlin at dberlin dot org>
- Date: Tue, 29 Jul 2003 16:35:52 -0700 (PDT)
- Subject: Re: Loop optimizer issues
On Tue, 29 Jul 2003, Zdenek Dvorak wrote:
> Hello,
>
> > > I've been thinking about this proposal and I am not convinced that it
> > > would be a good idea to merge the two branches.
> > >
> > > * The tree-ssa branch is primarily trying to replace RTL passes.
> > > This may include the loop optimizer. So far, it is not clear
> > > whether we will actually need to have a sophisticated loop
> > > optimizer at the RTL level (if at all). The only thing that
> > > comes to mind that may needed from RTL are:
> > > * instruction lengths/costs to guide the unroller
> > > * prefetching capabilities and memory costs to guide
> > > software pipelining and memory hierarchy optimizations.
> >
> > We do BIV-to-GIV conversion and some addressing mode selection in the RTL
> > loop optimizer. This is critical for targets such as the SH.
>
> this is done by the new rtl-level optimizer. The support probably is
> not flawless, but if you encounter some problems and provide me with
> more details, I am fairly confident I am able to fix them quickly.
>
> Zdenek
Look slike rtlopt-branch has problems for the SH:
dbmatch.i: In function `DBSetupGarbageObject':
dbmatch.i:4590: internal compiler error: Segmentation fault
I'll file a bug report.
Toshi