Hi!
On Wed, Apr 22, 2020 at 12:53:03AM -0400, Michael Meissner wrote:
> 2020-04-21 Michael Meissner <meiss...@linux.ibm.com>
>
> * config/rs6000/linux64.h (PCREL_SUPPORTED_BY_OS): Define to
> enable PC-relative addressing for -mcpu=future.
> * config/rs6000/rs6000-cpus.def (ISA_FUTURE_MASKS_SERVER): Move
> after OTHER_FUTURE_MASKS. Use OTHER_FUTURE_MASKS.
> * config/rs6000/rs6000.c (PCREL_SUPPORTED_BY_OS): If not defined,
> suppress PC-relative addressing.
> (rs6000_option_override_internal): Split up error messages
> checking for -mprefixed and -mpcrel. Enable -mpcrel if the target
> system supports it.
>
> --- /tmp/ud7l8s_linux64.h 2020-04-21 16:09:26.761209165 -0400
> +++ gcc/config/rs6000/linux64.h 2020-04-21 16:04:59.432652447 -0400
> @@ -640,3 +640,10 @@ extern int dot_symbols;
> enabling the __float128 keyword. */
> #undef TARGET_FLOAT128_ENABLE_TYPE
> #define TARGET_FLOAT128_ENABLE_TYPE 1
> +
> +/* Enable using prefixed PC-relative addressing on the 'future' machine if
> the
> + ABI supports it. The ELF v2 ABI only supports PC-relative relocations for
> + the medium code model. */
> +#define PCREL_SUPPORTED_BY_OS (TARGET_FUTURE && TARGET_PREFIXED
> \
> + && ELFv2_ABI_CHECK \
> + && (TARGET_CMODEL == CMODEL_MEDIUM))
No extra parens around comparisons please. If the macros malfunction
without it, fix the macros!
> + /* 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. */
> - if (TARGET_PCREL && TARGET_CMODEL != CMODEL_MEDIUM)
> + else if (TARGET_PCREL && TARGET_CMODEL != CMODEL_MEDIUM)
> {
> if ((rs6000_isa_flags_explicit & OPTION_MASK_PCREL) != 0)
> error ("%qs requires %qs", "-mpcrel", "-mcmodel=medium");
If pcrel is enabled by the first if(), we still need to test for cmodel,
I think? This same code won't work, of course.
Okay for trunk with that first thing fixed, and that second thing can be
dealt with in a later patch.
Thanks!
Segher
