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

On Tue, 21 Aug 2018 15:38:39 +1000
Anton Blanchard [off-list ref] wrote:

Hi Michael,

quoted

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