0005-Switch-Core-2-to-new-tuning

[Uros Bizjak]

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.

We are all looking forward for H.J.'s experimental stuff ;)

Thanks,
Uros.