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Re: 0005-Switch-Core-2-to-new-tuning
On Wed, Dec 01, 2010 at 10:50:27PM +0100, Uros Bizjak wrote:
> On Wed, Dec 1, 2010 at 10:37 AM, Maxim Kuvyrkov <maxim@codesourcery.com> wrote:
> > On Dec 1, 2010, at 3:00 AM, Jack Howarth wrote:
> >
> >> On Tue, Nov 30, 2010 at 01:51:41PM +0100, Uros Bizjak wrote:
> >>> On Tue, Nov 30, 2010 at 1:39 PM, Maxim Kuvyrkov <maxim@codesourcery.com> wrote:
> >>>> This patch switches Core 2 to "new" tuning that Core i7 uses.
> >>>>
> >>>> The "new" tuning very much resembles tuning for generic32 and generic64 CPUs. ?Generic tuning appears to provide best performance results on Core 2/i7 hardware.
> >>>>
> >>>> OK for trunk?
> >>>
> >>> Can you please summarize SPEC2k, SPEC2k6 and Polyhedron results for
> >>> patched and unpatched gcc?
> >>>
> >>> Thanks,
> >>> Uros.
> >>
> >> Uros,
> >> ? On x86-apple-darwin10, benchmarking the Polyhedron 2005 suite using a dual 2.8 GHz
> >> Xeon 2008 MacPro, I get the following results with -mtune=generic and -mtune=core2
> >> at -m64 and -m32. These are for r167305 with both 0005-Switch-Core-2-to-new-tuning
> >> and 0006-Core-2-i7-DFA applied.
> >> ...
> >> It is interesting that at -m32, -mtune=core2 shows a net
> >> improvement whereas at -m64 that option is a wash compared
> >> to -mtune=generic.
> >
> > That's what I expected. ?Jack, thanks for testing the patches on Polyhedron benchmarks.
>
> Thanks to H.J. and Jack for the results. These results are no worse
> than existing "generic" scheduling. Since this patch is mainly tuning
> (with a new DFA, of course), it is OK for mainline even in stage 3.
Uros,
Can you review the md file changes from Iain Sandoe's patch to enable mtune=core2 on darwin?
http://gcc.gnu.org/ml/gcc-patches/2010-08/msg01024.html
Once 0005-Switch-Core-2-to-new-tuning and 0006-Core-2-i7-DFA are committed to trunk, we would
like to switch intel darwin from generic to core2 tuning for gcc 4.6.
Jack
ps The patch was on hold until the core2 tuning performance issues were resolved.
>
> We are all looking forward for H.J.'s experimental stuff ;)
>
> Thanks,
> Uros.