Re: [PATCH 07/15] arm64: use -mno-implicit-float instead of -mgeneral-regs-only

From: Mark Rutland
Date: Fri Nov 03 2017 - 14:52:30 EST


On Fri, Nov 03, 2017 at 06:31:56PM +0000, Mark Rutland wrote:
> On Fri, Nov 03, 2017 at 10:11:52AM -0700, Sami Tolvanen wrote:
> > From: Greg Hackmann <ghackmann@xxxxxxxxxx>
> >
> > LLVM bug 30792 causes clang's AArch64 backend to crash compiling
> > arch/arm64/crypto/aes-ce-cipher.c. Replacing -mgeneral-regs-only with
> > -mno-implicit-float is the suggested workaround.
> >
> > Signed-off-by: Greg Hackmann <ghackmann@xxxxxxxxxx>
> > Cc: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
> > Signed-off-by: Sami Tolvanen <samitolvanen@xxxxxxxxxx>
>
> Just to check, what happens if you pass both to clang?

Apparently not. However, we can do:

-KBUILD_CFLAGS += -mgeneral-regs-only $(lseinstr) $(brokengasinst)
+KBUILD_CFLAGS += $(lseinstr) $(brokengasinst)
+# Clang workaround for https://bugs.llvm.org/show_bug.cgi?id=30792
+KBUILD_CFLAGS += $(call cc-option, -mno-implicit-float, -mgeneral-regs-only)

Thanks,
Mark.