Re: [PATCH, PR 49089] Don't split AVX256 unaligned loads by default on bdver1 and generic

["H.J. Lu" <hjl dot tools at gmail dot com>]

On Tue, Jun 14, 2011 at 4:59 PM, Fang, Changpeng <Changpeng.Fang@amd.com> wrote:
>
>
>>
>> So, is it OK to commit this patch to trunk, and H.J's original patch + this to 4.6 branch?
>
>>I have no problems on -mtune=Bulldozer. ?But I object -mtune=generic
>>change and did suggest a different approach for -mtune=generic.
>
> What's your suggested approach for -mtune=generic?
>
> My understanding of putting something into -mtune=generic is that all are happy, or
> some are willing to lose. This rule guided us not to turn on software prefetching for
> -mtune=generic.
>
> I would like to hear your suggestion that sandy bridge could get the performance while
> bulldozer does not lose from splitting avx256 unaligned loads!
>
> Thanks,

See:

http://gcc.gnu.org/ml/gcc-patches/2006-01/msg01045.html

for how we did it last time.

-- 
H.J.