RE: [PATCH][GCC][SLP][testsuite] Turn off vect-epilogue-nomask for slp-rect-3

[Richard Biener <rguenther@suse.de>]

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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.christina@arm.com>
> > >
> > > 	* gcc.dg/vect/slp-reduc-3.c: Turn off epilogue-nomask.
> > >
> > >
> > 
> > --
> > Richard Biener <rguenther@suse.de>
> > SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409
> > Nuernberg, Germany; GF: Felix Imendörffer; HRB 36809 (AG Nuernberg)
> 

-- 
Richard Biener <rguenther@suse.de>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Felix Imendörffer; HRB 36809 (AG Nuernberg)