[PATCH] arm: [testcase] Better narrow some bfloat16 testcase

Christophe Lyon christophe.lyon@linaro.org
Thu Nov 5 20:28:15 GMT 2020


On Thu, 5 Nov 2020 at 15:30, Andrea Corallo <andrea.corallo@arm.com> wrote:
>
> Christophe Lyon <christophe.lyon@linaro.org> writes:
>
> > On Thu, 5 Nov 2020 at 12:11, Andrea Corallo <andrea.corallo@arm.com> wrote:
> >>
> >> Christophe Lyon <christophe.lyon@linaro.org> writes:
> >>
> >> [...]
> >>
> >> >> I think you need to add -mfloat-abi=hard to the dg-additional-options
> >> >> otherwise vld1_lane_bf16_1.c
> >> >> fails on targets with a soft float-abi default (eg arm-linux-gnueabi).
> >> >>
> >> >> See bf16_vldn_1.c.
> >> >
> >> > Actually that's not sufficient because in turn we get:
> >> > /sysroot-arm-none-linux-gnueabi/usr/include/gnu/stubs.h:10:11: fatal
> >> > error: gnu/stubs-hard.h: No such file or directory
> >> >
> >> > So you should check that -mfloat-abi=hard is supported.
> >> >
> >> > Ditto for the vst tests.
> >>
> >> Hi Christophe,
> >>
> >> this patch should implement your suggestions.
> >>
> >> On my arm-none-linux-gnueabi setup the tests were already skipped
> >> as unsupported so if you could test and confirm this fixes the
> >> issue you see would be great.
> >
> > Do you know why they are unsupported in your setup?
>
> We probably have a different GCC configuration.  Could you share how
> it's configured your?
>
Sure, for instance:
--target=arm-none-linux-gnueabi --with-float=soft --with-mode=arm
--with-cpu=cortex-a9

> >> diff --git a/gcc/testsuite/lib/target-supports.exp b/gcc/testsuite/lib/target-supports.exp
> >> index 15f0649f8ae..2ab7e39756d 100644
> >> --- a/gcc/testsuite/lib/target-supports.exp
> >> +++ b/gcc/testsuite/lib/target-supports.exp
> >> @@ -5213,6 +5213,10 @@ proc check_effective_target_arm_v8_2a_bf16_neon_ok_nocache { } {
> >>          return 0;
> >>      }
> >>
> >> +    if { ! [check_effective_target_arm_hard_ok] } {
> >> + return 0;
> >> +    }
> >> +
> >>     foreach flags {"" "-mfloat-abi=hard -mfpu=neon-fp-armv8" "-mfloat-abi=softfp -mfpu=neon-fp-armv8" } {
> >>         if { [check_no_compiler_messages_nocache arm_v8_2a_bf16_neon_ok object {
> >>             #include <arm_neon.h>
> >
> > This seems strange since you would now exit early if
> > check_effective_target_arm_hard_ok is false, so you'll never need the
> > -mfloat-abi=softfp version of the flags.
>
> So IIUC your suggestion would be to test with higher priority softfp and
> in case we decide to go for hardfp make sure
> check_effective_target_arm_hard_ok is satisfied.  Am I correct?
>
ISTM that other tests that need hardfp check if it's supported in the
test, not in other effective targets.

For instance mve/intrinsics/mve_fpu1.c

I can see that quite a few tests that use -mfloat-abi=hard do not
check whether it's supported. Those I checked do not include
arm_neon.h and thus do not end up with the gnu/stubs-hard.h error
above.

> > BTW in general, I think softfp is tried before hard in the other
> > similar effective targets, any reason the order is different here?
>
> No idea.
>
> Thanks
>
>   Andrea


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