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

From: Mark Rutland
Date: Fri Nov 03 2017 - 14:32:04 EST


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?

If it works when you pass both...

> -KBUILD_CFLAGS += -mgeneral-regs-only $(lseinstr) $(brokengasinst)
> +ifeq ($(cc-name),clang)
> +# This is a workaround for https://bugs.llvm.org/show_bug.cgi?id=30792.
> +KBUILD_CFLAGS += -mno-implicit-float
> +else
> +KBUILD_CFLAGS += -mgeneral-regs-only
> +endif

... then this can be reduced to:

# This is a workaround for https://bugs.llvm.org/show_bug.cgi?id=30792
KBUILD_CFLAGS += $(call cc-option, -mno-implicit-float)

Thanks,
Mark.

> +KBUILD_CFLAGS += $(lseinstr) $(brokengasinst)
> KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
> KBUILD_CFLAGS += $(call cc-option, -mpc-relative-literal-loads)
> KBUILD_AFLAGS += $(lseinstr) $(brokengasinst)
> --
> 2.15.0.403.gc27cc4dac6-goog
>
>
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