Commit 5188129b authored by Huacai Chen's avatar Huacai Chen Committed by Ralf Baechle
Browse files

MIPS: Loongson-3: Improve -march option and move it to Platform 



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: default avatarHuacai Chen <chenhc@lemote.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12161/


Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent 6e526844

arch/mips/Makefile

+0 −10
Original line number Diff line number Diff line
@@ -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,)

arch/mips/loongson64/Platform

+21 −0
Original line number Diff line number Diff line
@@ -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

#

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