On Tue, Jun 29, 2021 at 07:06:14PM -0500, Segher Boessenkool wrote:
> On Thu, Jun 17, 2021 at 06:56:09PM -0400, Michael Meissner wrote:
> > The 'lp64' test
> > was needed because big endian 32-bit code cannot enable the IEEE 128-bit
> > floating point instructions.
>
> No, *does not* enable them. After
>
> diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
> index 2c249e186e1e..d4aac4164cfe 100644
> --- a/gcc/config/rs6000/rs6000.c
> +++ b/gcc/config/rs6000/rs6000.c
> @@ -4281,7 +4281,7 @@ rs6000_option_override_internal (bool global_init_p)
> rs6000_isa_flags &= ~OPTION_MASK_FLOAT128_HW;
> }
>
> - if (TARGET_FLOAT128_HW && !TARGET_64BIT)
> + if (0&& TARGET_FLOAT128_HW && !TARGET_64BIT)
> {
> if ((rs6000_isa_flags_explicit & OPTION_MASK_FLOAT128_HW) != 0)
> error ("%qs requires %qs", "%<-mfloat128-hardware%>", "-m64");
>
> you can compile fine with -m32 if you add -mfloat128-hardware as well
> (it is disabled for BE as well, that should be fixed as well a few lines
> up from there).
>
> Can you show any code that will not work please? Not allowing QP float
> with -m32 causes many more problems than just allowing it would.
I will in a bit, but it isn't that simple. Right now, all of the optimizations
for converting char/short/int -> __float128 (and presumably the other way)
don't work on 32-bit, because they want to split:
(parallel [(set (reg:KF <n>)
(float:KF (reg:SI <m>)))
(clobber (reg:DI <tmp>))])
Into:
(set (reg:DI <tmp>)
(sign_extend:DI (reg:SI <m>)))
(set (reg:KF <n>)
(float:KF (reg:DI <tmp>)))
And the sign_extend SI->DI doesn't exist in 32-bit.
> > * gcc.target/powerpc/float128-minmax.c: Adjust expected code for
> > power10.
> > * lib/target-supports.exp (check_effective_target_has_arch_pwr10):
> > New target support.
>
> Just "New." please.
>
> > /* { dg-require-effective-target powerpc_p9vector_ok } */
>
> Please try whether you can lose that line as well.
>
> Okay for trunk, and for 11 after the usual soak. Thanks!
>
>
> Segher
--
Michael Meissner, IBM
IBM, M/S 2506R, 550 King Street, Littleton, MA 01460-6245, USA
email: meiss...@linux.ibm.com, phone: +1 (978) 899-4797
