[PATCH] ARM: reset arm_fp16_format

[Richard Earnshaw]

On 01/06/2021 15:05, Martin Liška wrote:
> Hello.
> 
> The patch fixes https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98636#c20 
> where
> target option restore can be called and arm_fp16_format should be reset
> to ARM_FP16_FORMAT_NONE.
> 
> It fixes the ICE in the PR.
> 
> Can please ARM folks test me the patch on a Arm machine?
> Thanks,
> Martin
> 
> gcc/ChangeLog:
> 
>      PR target/98636
>      * config/arm/arm.c (arm_option_reconfigure_globals): Reset
>      the option if isa_bit_fp16 is not set.
> ---
>   gcc/config/arm/arm.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
> index 7b37e1b602c..4543f3c6b55 100644
> --- a/gcc/config/arm/arm.c
> +++ b/gcc/config/arm/arm.c
> @@ -3765,6 +3765,8 @@ arm_option_reconfigure_globals (void)
>       error ("selected fp16 options are incompatible");
>         arm_fp16_format = ARM_FP16_FORMAT_IEEE;
>       }
> +  else
> +    arm_fp16_format = ARM_FP16_FORMAT_NONE;
> 
>     arm_arch_cde = 0;
>     arm_arch_cde_coproc = 0;

My initial reaction is 'that can't be right'.

How would -mfp16-format=alternative ever work in this case?

R.