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Re: [PATCH], Tweak PowerPC movdi constraints
On Mon, Nov 21, 2016 at 01:27:59PM -0500, Michael Meissner wrote:
> On Fri, Nov 18, 2016 at 05:07:21PM -0600, Segher Boessenkool wrote:
> > On Fri, Nov 18, 2016 at 05:52:12PM -0500, Michael Meissner wrote:
> > > On Fri, Nov 18, 2016 at 04:43:40PM -0600, Segher Boessenkool wrote:
> > > > Could you also test with reload please? Just LE is enough I guess.
> > > > We'd like to keep reload working for GCC 7 at least, and these cost
> > > > prefixes tend to break mov patterns :-/
> > >
> > > Argh, I guess you are right, but then if reload doesn't work, I will likely
> > > submit the patch where there are three different movdi's (one for 32-bit
> > > without the change, one for 64-bit with reload, and one for 64-bit with lra).
> > > I would prefer not to do that.
> >
> > Let's hope it just works :-)
>
> I did test it over the weekend.
>
> 29 of the 30 spec 2006 benchmarks currently build with reload (gamess fails).
> The same 29 build and run with the new patch. Like the patch under LRA, there
> are no regressions in performance, and one FP benchmark is faster.
>
> Under LRA, sphinx3 is 2.5% faster (compared to LRA without the patch).
>
> Under reload, sphinx3 is roughly the same performance, but calculix is 3.8%
> faster.
Great, thanks for testing.
> Can I apply the patch?
Okay, if you change the changelog to say what the patch actually does ;-)
And please watch for fallout.
Segher