This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [patch] Merge to trunk from Graphite branch
Jack Howarth <howarth@bromo.med.uc.edu> wrote on 14/03/2010 05:30:36 PM:
> On Sun, Mar 14, 2010 at 08:22:59AM +0200, Ira Rosen wrote:
> >
> >
> > gcc-patches-owner@gcc.gnu.org wrote on 13/03/2010 09:19:00 PM:
> > >
> > > On Sat, Mar 13, 2010 at 12:15, Toon Moene <toon@moene.org> wrote:
> > > > Sebastian Pop wrote:
> > > >
> > > >> I just merged the Graphite branch back to trunk. ?This solved
> > > >> PR43349 for which I just added the testcase, as I already have
> > > >> taken care of it in the Graphite branch.
> > > >
> > > > Hmmm, is it just me or ...
> > > >
> > > > If I commpile:
> > > >
> > > > ? ? ?subroutine sum(a, b, c, n)
> > > > ? ? ?integer i, n
> > > > ? ? ?real a(n), b(n), c(n)
> > > > ? ? ?do i = 1, n
> > > > ? ? ? ? c(i) = a(i) + b(i)
> > > > ? ? ?enddo
> > > > ? ? ?end
> > > >
> > > > with -g -O3 -S and with -g -O3 -fgraphite-identity I strongly get
the
> > > > impression that -fgraphite-identity turns off vectorization (which
is
> > on by
> > > > default with -O3).
> > > >
> > > > Or am I missing something ...
> > >
> > > The vectorizer should be fixed to handle the code generated by
Graphite.
> > > The vectorizer expects to see a very particular form of code, and if
> > > anything differs from that pattern, it won't generate vector code.
> >
> > AFAIR, adding the following two passes cleans the code generated by
> > GRAPHITE:
> >
> > *** passes.c
> > --- passes.c
> > *************** init_optimization_passes (void)
> > *** 659,664 ****
> > --- 659,666 ----
> > NEXT_PASS (pass_graphite_transforms);
> > NEXT_PASS (pass_iv_canon);
> > + NEXT_PASS (pass_copy_prop);
> > + NEXT_PASS (pass_dce_loop);
> > NEXT_PASS (pass_if_conversion);
> > NEXT_PASS (pass_vectorize);
> >
> > (I think, it was suggested by Richard to solve similar problem, but I
can't
> > find the link).
> >
> > Ira
> >
> >
> > >
> > > Sebastian
>
> Ira,
> I believe you are thinking of Richard's proposed patch to add
versioning
> for constant strides for vectorization...
>
> http://gcc.gnu.org/ml/gcc-patches/2009-01/msg01174.html
>
> This patch has severe bit rot against current gcc trunk but would
> be nice to get into gcc trunk before gcc 4.5 if possible. I pinged
> Richard on this yesterday...
>
> http://gcc.gnu.org/ml/gcc-patches/2010-03/msg00518.html
Actually, I don't think that these patches are related.
Ira
>
> Jack