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

[Christophe Lyon]

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?

> 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.
BTW in general, I think softfp is tried before hard in the other
similar effective targets, any reason the order is different here?

Christophe

>
> Thanks!
>
>   Andrea
>