On Thu, 28 Nov 2019, Tamar Christina wrote:
> Hi Richi,
>
> > >
> > > This patch turns off vect-epilogue-nomask for slp-reduc-3 as it seems
> > > that the epiloque in this loop is vectorizable using SLP and smaller
> > > VF. Since this test expects there to be no SLP vectorization at all
> > > the testcase then fails for arm targets.
> >
> > Actually we do expect SLP vectorization, just the counting might go wrong.
> >
> > What's the actual FAIL for arm?
>
> I should have worded this better considering the testcase literally contains
> SLP in the name...
>
> The failure is for the XFAIL
>
> /* { dg-final { scan-tree-dump-times "vectorizing stmts using SLP" 1 "vect" {
> xfail { vect_widen_sum_hi_to_si_pattern || { ! vect_unpack } } } } } */
>
> And my understanding as to what is happening is that without epiloque no mask
> it would only try HI modes, but thanks to the epiloques nomask
> It tries QI mode as well which succeeds. The xfail then generates an xpass
> since the condition on it checks for HI to SI and not QI.
>
> So I disabled the epiloque mask since it seems to violate the conditions the
> test actually wanted to test for.
>
> Not quite sure why it's failing only on Arm though.
No idea.
I agree about the resolution so the patch is fine.
Thanks,
RIchard.
> Regards,
> Tamar
>
> >
> > Disabling epilogue vect is of course OK if it simplifies things.
> >
> > > Regtested on arm-none-eabi and no issues.
> > >
> > > Ok for trunk?
> >
> > > Thanks,
> > > Tamar
> > >
> > > gcc/testsuite/ChangeLog:
> > >
> > > 2019-11-28 Tamar Christina <tamar.christ...@arm.com>
> > >
> > > * gcc.dg/vect/slp-reduc-3.c: Turn off epilogue-nomask.
> > >
> > >
> >
> > --
> > Richard Biener <rguent...@suse.de>
> > SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409
> > Nuernberg, Germany; GF: Felix Imendörffer; HRB 36809 (AG Nuernberg)
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Felix Imendörffer; HRB 36809 (AG Nuernberg)
