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In-Reply-To: <20201113190824.GA1477315@ubuntu-m3-large-x86>
From:   Nick Desaulniers <ndesaulniers@google.com>
Date:   Fri, 13 Nov 2020 11:42:03 -0800
Message-ID: <CAKwvOdkEtTQhDRFRV_d66FyhQBe536vRbOW=fQjesiHz3dfeBA@mail.gmail.com>
Subject: Re: Error: invalid switch -me200
To:     Nathan Chancellor <natechancellor@gmail.com>,
        Michael Ellerman <mpe@ellerman.id.au>
Cc:     =?UTF-8?B?RsSBbmctcnXDrCBTw7JuZw==?= <maskray@google.com>,
        kernel test robot <lkp@intel.com>, kbuild-all@lists.01.org,
        clang-built-linux <clang-built-linux@googlegroups.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Masahiro Yamada <masahiroy@kernel.org>,
        linuxppc-dev <linuxppc-dev@lists.ozlabs.org>
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+ MPE, PPC

On Fri, Nov 13, 2020 at 11:08 AM Nathan Chancellor
<natechancellor@gmail.com> wrote:
>
> On Fri, Nov 13, 2020 at 09:28:03AM -0800, F=C4=81ng-ru=C3=AC S=C3=B2ng wr=
ote:
> > On Thu, Nov 12, 2020 at 7:22 PM kernel test robot <lkp@intel.com> wrote=
:
> > >
> > > Hi Fangrui,
> > >
> > > FYI, the error/warning still remains.
> > >
> > > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linu=
x.git master
> > > head:   585e5b17b92dead8a3aca4e3c9876fbca5f7e0ba
> > > commit: ca9b31f6bb9c6aa9b4e5f0792f39a97bbffb8c51 Makefile: Fix GCC_TO=
OLCHAIN_DIR prefix for Clang cross compilation
> > > date:   4 months ago
> > > config: powerpc-randconfig-r031-20201113 (attached as .config)

^ randconfig

> > > compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project =
9e0c35655b6e8186baef8840b26ba4090503b554)
> > > reproduce (this is a W=3D1 build):
> > >         wget https://raw.githubusercontent.com/intel/lkp-tests/master=
/sbin/make.cross -O ~/bin/make.cross
> > >         chmod +x ~/bin/make.cross
> > >         # install powerpc cross compiling tool for clang build
> > >         # apt-get install binutils-powerpc-linux-gnu
> > >         # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/li=
nux.git/commit/?id=3Dca9b31f6bb9c6aa9b4e5f0792f39a97bbffb8c51
> > >         git remote add linus https://git.kernel.org/pub/scm/linux/ker=
nel/git/torvalds/linux.git
> > >         git fetch --no-tags linus master
> > >         git checkout ca9b31f6bb9c6aa9b4e5f0792f39a97bbffb8c51
> > >         # save the attached .config to linux build tree
> > >         COMPILER_INSTALL_PATH=3D$HOME/0day COMPILER=3Dclang make.cros=
s ARCH=3Dpowerpc
> > >
> > > If you fix the issue, kindly add following tag as appropriate
> > > Reported-by: kernel test robot <lkp@intel.com>
> > >
> > > All errors (new ones prefixed by >>):
> > >
> > >    Assembler messages:
> > > >> Error: invalid switch -me200
> > > >> Error: unrecognized option -me200
> > >    clang-12: error: assembler command failed with exit code 1 (use -v=
 to see invocation)
> > >    make[2]: *** [scripts/Makefile.build:281: scripts/mod/empty.o] Err=
or 1
> > >    make[2]: Target '__build' not remade because of errors.
> > >    make[1]: *** [Makefile:1174: prepare0] Error 2
> > >    make[1]: Target 'prepare' not remade because of errors.
> > >    make: *** [Makefile:185: __sub-make] Error 2
> > >    make: Target 'prepare' not remade because of errors.
> > >
> > > ---
> > > 0-DAY CI Kernel Test Service, Intel Corporation
> > > https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
> >
> > This can be ignored. The LLVM integrated assembler does not recognize
> > -me200 (-Wa,-me200 in arch/powerpc/Makefile). I guess the GNU as -m
> > option is similar to .arch or .machine and controls what instructions
> > are recognized. The integrated assembler tends to support all
> > instructions (conditional supporting some instructions has some
> > challenges; in the end I have patched parsing but ignoring `.arch` for
> > x86-64 and ignoring `.machine ppc64` for ppc64)
> >
> > (In addition, e200 is a 32-bit Power ISA microprocessor. 32-bit
> > support may get less attention in LLVM.)
>
> This is also not a clang specific issue, I see the exact same error
> with GCC 10.2.0 and binutils 2.35.
>
> $ make -skj64 ARCH=3Dpowerpc CROSS_COMPILE=3Dpowerpc64-linux- olddefconfi=
g vmlinux

Does using a non 64b triple produce the same failure?

> ...
> Error: invalid switch -me200
> Error: unrecognized option -me200

There's a block in  arch/powerpc/Makefile:
248 cpu-as-$(CONFIG_40x)    +=3D -Wa,-m405
249 cpu-as-$(CONFIG_44x)    +=3D -Wa,-m440
250 cpu-as-$(CONFIG_ALTIVEC)  +=3D $(call
as-option,-Wa$(comma)-maltivec)
251 cpu-as-$(CONFIG_E200)   +=3D -Wa,-me200
252 cpu-as-$(CONFIG_E500)   +=3D -Wa,-me500

Are those all broken configs, or is Kconfig messed up such that
randconfig can select these when it should not?
--=20
Thanks,
~Nick Desaulniers