[PATCH] powerpc/Makefiles: Fix clang/llvm build

[Nicholas Piggin]

On Tue, 21 Aug 2018 15:38:39 +1000
Anton Blanchard <anton at ozlabs.org> wrote:

> Hi Michael,
> 
> > This breaks GCC 4.6.3 at least, which we still support:
> > 
> >   Assembler messages:
> >   Error: invalid switch -mpower8
> >   Error: unrecognized option -mpower8
> >   ../scripts/mod/empty.c:1:0: fatal error: error closing -: Broken
> > pipe  
> 
> Yuck. We have POWER8 instructions in our assembly code, and a toolchain
> that doesn't understand the -mpower8 flag, but has support for
> power8 instructions.
> 
> This is what I see on clang with -mpower7:
> 
> /tmp/sstep-2afa55.s:7584: Error: unrecognized opcode: `lbarx'
> /tmp/sstep-2afa55.s:7626: Error: unrecognized opcode: `stbcx.'
> /tmp/sstep-2afa55.s:8077: Error: unrecognized opcode: `lharx'
> /tmp/sstep-2afa55.s:8140: Error: unrecognized opcode: `stbcx.'
> 
> Nick: any suggestions?

 cpu-as-$(CONFIG_PPC_BOOK3S_64)	+= $(call as-option,-Wa$(comma)-mpower8,-Wa$(comma)-mpower4)

?

Thanks,
Nick