If GCC >= 4.9 and Binutils >=2.25, we use -march=loongson3a, otherwise we use -march=mips64r2, this can slightly improve performance. Besides, arch/mips/loongson64/Platform is a better location rather than arch/ mips/Makefile. Signed-off-by: Huacai Chen <chenhc@xxxxxxxxxx> --- arch/mips/Makefile | 10 ---------- arch/mips/loongson64/Platform | 21 +++++++++++++++++++++ 2 files changed, 21 insertions(+), 10 deletions(-) diff --git a/arch/mips/Makefile b/arch/mips/Makefile index 3f70ba5..e78d60d 100644 --- a/arch/mips/Makefile +++ b/arch/mips/Makefile @@ -166,16 +166,6 @@ cflags-$(CONFIG_CPU_CAVIUM_OCTEON) += -Wa,-march=octeon endif cflags-$(CONFIG_CAVIUM_CN63XXP1) += -Wa,-mfix-cn63xxp1 cflags-$(CONFIG_CPU_BMIPS) += -march=mips32 -Wa,-mips32 -Wa,--trap -# -# binutils from v2.25 on and gcc starting from v4.9.0 treat -march=loongson3a -# as MIPS64 R1; older versions as just R1. This leaves the possibility open -# that GCC might generate R2 code for -march=loongson3a which then is rejected -# by GAS. The cc-option can't probe for this behaviour so -march=loongson3a -# can't easily be used safely within the kbuild framework. -# -cflags-$(CONFIG_CPU_LOONGSON3) += \ - $(call cc-option,-march=mips64r2,-mips64r2 -U_MIPS_ISA -D_MIPS_ISA=_MIPS_ISA_MIPS64) \ - -Wa,-mips64r2 -Wa,--trap cflags-$(CONFIG_CPU_R4000_WORKAROUNDS) += $(call cc-option,-mfix-r4000,) cflags-$(CONFIG_CPU_R4400_WORKAROUNDS) += $(call cc-option,-mfix-r4400,) diff --git a/arch/mips/loongson64/Platform b/arch/mips/loongson64/Platform index 2e48e83..85d8089 100644 --- a/arch/mips/loongson64/Platform +++ b/arch/mips/loongson64/Platform @@ -22,6 +22,27 @@ ifdef CONFIG_CPU_LOONGSON2F_WORKAROUNDS endif endif +cflags-$(CONFIG_CPU_LOONGSON3) += -Wa,--trap +# +# binutils from v2.25 on and gcc starting from v4.9.0 treat -march=loongson3a +# as MIPS64 R2; older versions as just R1. This leaves the possibility open +# that GCC might generate R2 code for -march=loongson3a which then is rejected +# 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, 22500000, y), y) + cflags-$(CONFIG_CPU_LOONGSON3) += \ + $(call cc-option,-march=loongson3a -U_MIPS_ISA -D_MIPS_ISA=_MIPS_ISA_MIPS64) + else + cflags-$(CONFIG_CPU_LOONGSON3) += \ + $(call cc-option,-march=mips64r2,-mips64r2 -U_MIPS_ISA -D_MIPS_ISA=_MIPS_ISA_MIPS64) + endif +else + cflags-$(CONFIG_CPU_LOONGSON3) += \ + $(call cc-option,-march=mips64r2,-mips64r2 -U_MIPS_ISA -D_MIPS_ISA=_MIPS_ISA_MIPS64) +endif + # # Loongson Machines' Support # -- 2.4.6
