[PATCH][GCC] arm: add armv9-a architecture to -march

[Christophe Lyon]

Hi,


On Tue, Nov 9, 2021 at 12:36 PM Przemyslaw Wirkus via Gcc-patches <
gcc-patches@gcc.gnu.org> wrote:

> > > > -----Original Message-----
> > > > From: Przemyslaw Wirkus
> > > > Sent: 18 October 2021 10:37
> > > > To: gcc-patches@gcc.gnu.org
> > > > Cc: Richard Earnshaw <Richard.Earnshaw@arm.com>; Ramana
> > > > Radhakrishnan <Ramana.Radhakrishnan@arm.com>; Kyrylo Tkachov
> > > > <Kyrylo.Tkachov@arm.com>; nickc@redhat.com
> > > > Subject: [PATCH][GCC] arm: add armv9-a architecture to -march
> > > >
> > > > Hi,
> > > >
> > > > This patch is adding `armv9-a` to -march in Arm GCC.
> > > >
> > > > In this patch:
> > > >   + Add `armv9-a` to -march.
> > > >   + Update multilib with armv9-a and armv9-a+simd.
> > > >
> > > > After this patch three additional multilib directories are available:
> > > >
> > > > $ arm-none-eabi-gcc --print-multi-lib .; [...vanilla multi-lib
> > > > dirs...] thumb/v9-a/nofp;@mthumb@march=armv9-a@mfloat-abi=soft
> > > > thumb/v9-a+simd/softfp;@mthumb@march=armv9-a+simd@mfloat-
> > > > abi=softfp
> > > > thumb/v9-a+simd/hard;@mthumb@march=armv9-a+simd@mfloat-
> > > > abi=hard
> > > >
>

This is causing a GCC build failure when using "old" binutils (I'm using
2.36.1),
because the new -march=armv9-a option is not supported. This breaks the
multilib support.

I don't remember how we handled similar cases in the past? Is that just
"expected", and
"current" GCC needs "current" binutils, or should we have a multilib list
dependent on
the actual binutils support? (I think this is not the case, and it sounds
like an undesirable
extra complication in an already overcrowded mutilib-Makefile)

Christophe

> > > New multi-lib directories under
> > > > $GCC_INSTALL_DIE/lib/gcc/arm-none-eabi/12.0.0/thumb are created:
> > > >
> > > > thumb/
> > > > +--- v9-a
> > > > |    |--- nofp
> > > > |
> > > > +--- v9-a+simd
> > > >      |--- hard
> > > >      |--- softfp
> > > >
> > > > Regtested on arm-none-eabi cross and no issues.
> > > >
> > > > OK for master?
>
> Thanks.
>
> commit 32ba7860ccaddd5219e6dae94a3d0653e124c9dd
>
> > Ok.
> > Thanks,
> > Kyrill
> >
> >
> > > >
> > > > gcc/ChangeLog:
> > > >
> > > >   * config/arm/arm-cpus.in (armv9): New define.
> > > >   (ARMv9a): New group.
> > > >   (armv9-a): New arch definition.
> > > >   * config/arm/arm-tables.opt: Regenerate.
> > > >   * config/arm/arm.h (BASE_ARCH_9A): New arch enum value.
> > > >   * config/arm/t-aprofile: Added armv9-a and armv9+simd.
> > > >   * config/arm/t-arm-elf: Added arm9-a, v9_fps and all_v9_archs
> > > >   to MULTILIB_MATCHES.
> > > >   * config/arm/t-multilib: Added v9_a_nosimd_variants and
> > > >   v9_a_simd_variants to MULTILIB_MATCHES.
> > > >   * doc/invoke.texi: Update docs.
> > > >
> > > > gcc/testsuite/ChangeLog:
> > > >
> > > >   * gcc.target/arm/multilib.exp: Update test with armv9-a entries.
> > > >   * lib/target-supports.exp (v9a): Add new armflag.
> > > >   (__ARM_ARCH_9A__): Add new armdef.
> > > >
> > > > --
> > > > kind regards,
> > > > Przemyslaw Wirkus
>
>