Hi Jeevitha,
on 2023/8/21 18:32, jeevitha wrote:
> Hi All,
>
> The following patch has been bootstrapped and regtested on powerpc64-linux.
I think we should test this on powerpc64le-linux P8 or P9 (no P10) as well.
>
> It is currently possible to incorrectly enable PCREL for targets that do not
> officially support it. Disable PCREL for targets that do not support it.
>
> 2023-08-21 Jeevitha Palanisamy <jeevi...@linux.ibm.com>
>
> gcc/
> PR target/111045
> * config/rs6000/rs6000.cc (rs6000_option_override_internal): Disable
> PCREL
> for unsupported targets.
>
> diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
> index efe9adc..4838f8c 100644
> --- a/gcc/config/rs6000/rs6000.cc
> +++ b/gcc/config/rs6000/rs6000.cc
> @@ -4232,6 +4232,9 @@ rs6000_option_override_internal (bool global_init_p)
> rs6000_isa_flags &= ~OPTION_MASK_FLOAT128_HW;
> }
>
> + if (!rs6000_pcrel_p())
Nit: Only do this check when TARGET_PCREL, one space before "()",
that is "...pcrel_p ()".
I think this should be moved to be with the hunk on PCREL:
/* If the ABI has support for PC-relative relocations, enable it by default.
This test depends on the sub-target tests above setting the code model to
medium for ELF v2 systems. */
if (PCREL_SUPPORTED_BY_OS
&& (rs6000_isa_flags_explicit & OPTION_MASK_PCREL) == 0)
rs6000_isa_flags |= OPTION_MASK_PCREL;
/* -mpcrel requires -mcmodel=medium, but we can't check TARGET_CMODEL until
after the subtarget override options are done. */
else if (TARGET_PCREL && TARGET_CMODEL != CMODEL_MEDIUM)
{
if ((rs6000_isa_flags_explicit & OPTION_MASK_PCREL) != 0)
error ("%qs requires %qs", "-mpcrel", "-mcmodel=medium");
rs6000_isa_flags &= ~OPTION_MASK_PCREL;
}
==>
else if (TARGET_PCREL && !rs6000_pcrel_p ())
rs6000_isa_flags &= ~OPTION_MASK_PCREL;
Use DEFAULT_ABI != ABI_ELFv2 seems more straightforward, but I guessed the
reason why you used rs6000_pcrel_p is to avoid scattered conditions, it's
fine to me. Besides, I think we want one error for explicit -mpcrel on
unsupported targets just similar to the above cmodel?
BR,
Kewen
> + rs6000_isa_flags &= ~OPTION_MASK_PCREL;
> +
> /* Enable -mprefixed by default on power10 systems. */
> if (TARGET_POWER10 && (rs6000_isa_flags_explicit & OPTION_MASK_PREFIXED)
> == 0)
> rs6000_isa_flags |= OPTION_MASK_PREFIXED;
>
