Re: [PATCH][ARM] Fix test armv8_2-fp16-move-1.c

[Sudakshina Das <sudi dot das at arm dot com>]

On 22/11/17 15:21, Kyrill Tkachov wrote:
> On 22/11/17 11:25, Sudi Das wrote:
> > Hi Kyrill and Christophe
> >
> >
> > In case of soft fp testing, there are other assembly directives apart 
> > from the vmov one which are also failing. The directives probably 
> > make more sense in the hard fp context so instead of removing the 
> > vmov, I have added the -mfloat-abi=hard option.
> >
> > Is this ok for trunk? If yes could someone post it on my behalf?
> >
> > Sudi
>
> Thanks Sudi,
>
> You're right, this whole test isn't written with softfp in mind. We 
> might as well restrict it to -mfloat-abi=hard.
> I've committed the patch with r255061.
Hi Kyriil

Thanks for the commit!

> Would you like to get commit access to the SVN repo?
> If you complete the form at 
> https://sourceware.org/cgi-bin/pdw/ps_form.cgi
> using my email address as the approver we can get that sorted out :)

Thanks again for the invite. I have filled out the form! :)

Sudi


> Kyrill
>
> > *** gcc/testsuite/ChangeLog ***
> >
> > 2017-11-22  Sudakshina Das  <sudi.das@arm.com>
> >
> >     * gcc.target/arm/armv8_2-fp16-move-1.c: Add -mfloat-abi=hard option.
> >
> >
> >
> >
> > From: Kyrill Tkachov <kyrylo.tkachov@foss.arm.com>
> > Sent: Monday, November 20, 2017 2:20 PM
> > To: Christophe Lyon
> > Cc: Sudi Das; gcc-patches@gcc.gnu.org; nd; Ramana Radhakrishnan; 
> > Richard Earnshaw
> > Subject: Re: [PATCH][ARM] Fix test armv8_2-fp16-move-1.c
> >
> >
> > On 20/11/17 14:14, Christophe Lyon wrote:
> > > Hi,
> > >
> > > On 17 November 2017 at 12:12, Kyrill  Tkachov
> > > <kyrylo.tkachov@foss.arm.com> wrote:
> > > > On 17/11/17 10:45, Sudi Das wrote:
> > > > > Hi Kyrill
> > > > >
> > > > > Thanks I have made the change.
> > > > Thanks Sudi, I've committed this on your behalf with r254863.
> > > >
> > > > Kyrill
> > > >
> > > >
> > > > > Sudi
> > > > >
> > > > >
> > > > >
> > > > > From: Kyrill Tkachov <kyrylo.tkachov@foss.arm.com>
> > > > > Sent: Thursday, November 16, 2017 5:03 PM
> > > > > To: Sudi Das; gcc-patches@gcc.gnu.org
> > > > > Cc: nd; Ramana Radhakrishnan; Richard Earnshaw
> > > > > Subject: Re: [PATCH][ARM] Fix test armv8_2-fp16-move-1.c
> > > > >
> > > > > Hi Sudi,
> > > > >
> > > > > On 16/11/17 16:37, Sudi Das wrote:
> > > > > > Hi
> > > > > >
> > > > > > This patch fixes the test case armv8_2-fp16-move-1.c for
> > > > > > arm-none-linux-gnueabihf where 2 of the scan-assembler directives 
> > > > > > were
> > > > > > failing. We now generate less vmov between core and VFP registers.
> > > > > > Thus changing those directives to reflect that.
> > > > > >
> > > > > > Is this ok for trunk?
> > > > > > If yes could someone commit it on my behalf?
> > > > > >
> > > > > > Sudi
> > > > > >
> > > > > >
> > > > > > *** gcc/testsuite/ChangeLog ***
> > > > > >
> > > > > > 2017-11-16  Sudakshina Das  <sudi.das@arm.com>
> > > > > >
> > > > > >              * gcc.target/arm/armv8_2-fp16-move-1.c: Edit vmov
> > > > > > scan-assembler
> > > > > >              directives.
> > > > > diff --git a/gcc/testsuite/gcc.target/arm/armv8_2-fp16-move-1.c
> > > > > b/gcc/testsuite/gcc.target/arm/armv8_2-fp16-move-1.c
> > > > > index bb4e68f..0ed8560 100644
> > > > > --- a/gcc/testsuite/gcc.target/arm/armv8_2-fp16-move-1.c
> > > > > +++ b/gcc/testsuite/gcc.target/arm/armv8_2-fp16-move-1.c
> > > > > @@ -101,8 +101,8 @@ test_select_8 (__fp16 a, __fp16 b, __fp16 c)
> > > > >       /* { dg-final { scan-assembler-times {vselgt\.f16\ts[0-9]+, 
> > > > > s[0-9]+,
> > > > > s[0-9]+} 1 } }  */
> > > > >       /* { dg-final { scan-assembler-times {vselge\.f16\ts[0-9]+, 
> > > > > s[0-9]+,
> > > > > s[0-9]+} 1 } }  */
> > > > >       -/* { dg-final { scan-assembler-times {vmov\.f16\ts[0-9]+, 
> > > > > r[0-9]+} 4 }
> > > > > }  */
> > > > > -/* { dg-final { scan-assembler-times {vmov\.f16\tr[0-9]+, 
> > > > > s[0-9]+} 4 } }
> > > > > */
> > > > > +/* { dg-final { scan-assembler-times {vmov\.f16\ts[0-9]+, 
> > > > > r[0-9]+} 2 } }
> > > > > */
> > > > > +/* { dg-final { scan-assembler-times {vmov\ts[0-9]+, s[0-9]+} 4 } 
> > > > > }  */
> > > > >       Some of the moves between core and fp registers were the 
> > > > > result of
> > > > > inefficient codegen and in hindsight
> > > > > scanning for them was not very useful. Now that we emit only the 
> > > > > required
> > > > > ones I think scanning for the plain
> > > > > vmovs between two S-registers doesn't test anything useful.
> > > > > So can you please just remove the second scan-assembler directive 
> > > > > here?
> > > You are probably already aware of that: the tests fail on
> > > arm-none-linux-gnueabi/arm-none-eabi
> > > FAIL: gcc.target/arm/armv8_2-fp16-move-1.c scan-assembler-times
> > > vmov\\.f16\\ts[0-9]+, r[0-9]+ 2 (found 38 times)
> > >
> > > but this is not a regression, the previous version of the test had the
> > > same problem.
> > Grrr, that's because the softfp ABI necessitates moves between core and
> > FP registers,
> > so scanning for a particular number of vmovs between them is just not
> > gonna be stable across
> > soft-float ABIs. At this point I'd just remove the scan for vmovs
> > completely as it doesn't
> > seem to check anything useful.
> >
> > A patch to remove that scan for VMOV is pre-approved.
> >
> > Thanks for reminding me of this Christophe, softfp tends to slip my 
> > mind :(
> > Kyrill
> >
> > > Christophe
> > >
> > > > > Thanks,
> > > > > Kyrill