RE: [PATCH 05/13] arm: Add support for VPR_REG in arm_class_likely_spilled_p

[Kyrylo Tkachov via Gcc-patches]

> -----Original Message-----
> From: Gcc-patches <gcc-patches-
> bounces+kyrylo.tkachov=arm....@gcc.gnu.org> On Behalf Of Christophe
> Lyon via Gcc-patches
> Sent: 07 September 2021 10:17
> To: gcc-patches@gcc.gnu.org
> Subject: [PATCH 05/13] arm: Add support for VPR_REG in
> arm_class_likely_spilled_p
> 
> VPR_REG is the only register in its class, so it should be handled by
> TARGET_CLASS_LIKELY_SPILLED_P.  No test fails without this patch, but
> it seems it should be implemented.

The documentation for the hook does recommend returning true when there is only 
one register in the class.
So this seems sensible to me. It's supposed to affect optimisation rather than 
correctness so I'm in favour of it.
Ok.
Thanks,
Kyrill

> 
> 2021-09-01  Christophe Lyon  <christophe.l...@foss.st.com>
> 
>       gcc/
>       * config/arm/arm.c (arm_class_likely_spilled_p): Handle VPR_REG.
> 
> diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
> index 11dafc70067..1222cb0d0fe 100644
> --- a/gcc/config/arm/arm.c
> +++ b/gcc/config/arm/arm.c
> @@ -29307,6 +29307,9 @@ arm_class_likely_spilled_p (reg_class_t rclass)
>        || rclass  == CC_REG)
>      return true;
> 
> +  if (TARGET_HAVE_MVE && (rclass == VPR_REG))
> +    return true;
> +
>    return false;
>  }
> 
> --
> 2.25.1