[patch, powerpc] increase array alignment for Altivec

[Bill Schmidt]

On Thu, 2013-05-23 at 08:54 -0600, Sandra Loosemore wrote:
> On 05/23/2013 06:29 AM, Bill Schmidt wrote:
> >
> > Sandra and David,
> >
> > The array-alignment patch is performance-neutral with respect to
> > CPU2006.  All variations were in the noise range.
> 
> Well, that settles it; I don't see any reason to pursue the patch any 
> further if it's not a performance win after all.  It probably helped on 
> some specific program or benchmark our original customer was interested 
> in but that was in an older version of GCC, etc.
> 
> Bill, thanks very much for helping with this.

I'm not sure that's the right message to take away here -- this was just
verifying that we didn't see a benchmarking problem with the patch.  It
seems likely that the patch does have benefits; they just aren't exposed
in the particular benchmarks in SPEC CPU2006.

I think the patch is worth pursuing, since there aren't any negative
consequences in reporting benchmarks.

Thanks,
Bill

> 
> -Sandra
>