On Thu, Jan 20, 2022 at 1:40 PM Nathan Chancellor <nathan@xxxxxxxxxx> wrote:
>
> This Makefile checks that GCC is 4.9 or newer, which is redundant after
> commit 76ae847497bc ("Documentation: raise minimum supported version of
> GCC to 5.1"), so cc-option can be removed.
>
> Clang does not support -march=loongson3a so it needs to continue to use
> -march=mips64r2, along with binutils less than 2.25, so check that both
> GCC and binutils 2.25 or newer are being used before using
> -march=loongson3a. These flags do not need to be checked with cc-option
> anymore because all GCC versions support -march=loongson3a and
> -march=mips64r2 and all clang versions support -march=mips64r2.
>
> Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx>
Thanks for the patch. I wonder why `_MIPS_ISA` only seems to be set at
all for `-march=loongson3a` AFAICT, though that question is orthogonal
to this patch. Perhaps the Loongson or MIPS maintainers know more?
Otherwise seems like most uses of _MIPS_ISA can either be deleted or
simplified now.
Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
> ---
> arch/mips/loongson64/Platform | 13 +++----------
> 1 file changed, 3 insertions(+), 10 deletions(-)
>
> diff --git a/arch/mips/loongson64/Platform b/arch/mips/loongson64/Platform
> index 3e660d6d3c2b..981d3abc150e 100644
> --- a/arch/mips/loongson64/Platform
> +++ b/arch/mips/loongson64/Platform
> @@ -12,17 +12,10 @@ cflags-$(CONFIG_CPU_LOONGSON64) += -Wa,--trap
> # by GAS. The cc-option can't probe for this behaviour so -march=loongson3a
> # can't easily be used safely within the kbuild framework.
> #
> -ifeq ($(call cc-ifversion, -ge, 0409, y), y)
> - ifeq ($(call ld-ifversion, -ge, 22500, y), y)
> - cflags-$(CONFIG_CPU_LOONGSON64) += \
> - $(call cc-option,-march=loongson3a -U_MIPS_ISA -D_MIPS_ISA=_MIPS_ISA_MIPS64)
> - else
> - cflags-$(CONFIG_CPU_LOONGSON64) += \
> - $(call cc-option,-march=mips64r2,-mips64r2 -U_MIPS_ISA -D_MIPS_ISA=_MIPS_ISA_MIPS64)
> - endif
> +ifeq ($(CONFIG_CC_IS_GCC)$(call ld-ifversion, -ge, 22500, y), yy)
> + cflags-$(CONFIG_CPU_LOONGSON64) += -march=loongson3a -U_MIPS_ISA -D_MIPS_ISA=_MIPS_ISA_MIPS64
> else
> - cflags-$(CONFIG_CPU_LOONGSON64) += \
> - $(call cc-option,-march=mips64r2,-mips64r2 -U_MIPS_ISA -D_MIPS_ISA=_MIPS_ISA_MIPS64)
> + cflags-$(CONFIG_CPU_LOONGSON64) += -march=mips64r2
> endif
>
> # Some -march= flags enable MMI instructions, and GCC complains about that
>
> base-commit: 2c271fe77d52a0555161926c232cd5bc07178b39
> --
> 2.34.1
>
--
Thanks,
~Nick Desaulniers
