makefile_32.cpu

linux 内核源代码

# CPU tuning section - shared with UML.
# Must change only cflags-y (or [yn]), not CFLAGS! That makes a difference for UML.

#-mtune exists since gcc 3.4
HAS_MTUNE	:= $(call cc-option-yn, -mtune=i386)
ifeq ($(HAS_MTUNE),y)
tune		= $(call cc-option,-mtune=$(1),$(2))
else
tune		= $(call cc-option,-mcpu=$(1),$(2))
endif

align := $(cc-option-align)
cflags-$(CONFIG_M386)		+= -march=i386
cflags-$(CONFIG_M486)		+= -march=i486
cflags-$(CONFIG_M586)		+= -march=i586
cflags-$(CONFIG_M586TSC)	+= -march=i586
cflags-$(CONFIG_M586MMX)	+= -march=pentium-mmx
cflags-$(CONFIG_M686)		+= -march=i686
cflags-$(CONFIG_MPENTIUMII)	+= -march=i686 $(call tune,pentium2)
cflags-$(CONFIG_MPENTIUMIII)	+= -march=i686 $(call tune,pentium3)
cflags-$(CONFIG_MPENTIUMM)	+= -march=i686 $(call tune,pentium3)
cflags-$(CONFIG_MPENTIUM4)	+= -march=i686 $(call tune,pentium4)
cflags-$(CONFIG_MK6)		+= -march=k6
# Please note, that patches that add -march=athlon-xp and friends are pointless.
# They make zero difference whatsosever to performance at this time.
cflags-$(CONFIG_MK7)		+= -march=athlon
cflags-$(CONFIG_MK8)		+= $(call cc-option,-march=k8,-march=athlon)
cflags-$(CONFIG_MCRUSOE)	+= -march=i686 $(align)-functions=0 $(align)-jumps=0 $(align)-loops=0
cflags-$(CONFIG_MEFFICEON)	+= -march=i686 $(call tune,pentium3) $(align)-functions=0 $(align)-jumps=0 $(align)-loops=0
cflags-$(CONFIG_MWINCHIPC6)	+= $(call cc-option,-march=winchip-c6,-march=i586)
cflags-$(CONFIG_MWINCHIP2)	+= $(call cc-option,-march=winchip2,-march=i586)
cflags-$(CONFIG_MWINCHIP3D)	+= $(call cc-option,-march=winchip2,-march=i586)
cflags-$(CONFIG_MCYRIXIII)	+= $(call cc-option,-march=c3,-march=i486) $(align)-functions=0 $(align)-jumps=0 $(align)-loops=0
cflags-$(CONFIG_MVIAC3_2)	+= $(call cc-option,-march=c3-2,-march=i686)
cflags-$(CONFIG_MVIAC7)		+= -march=i686
cflags-$(CONFIG_MCORE2)		+= -march=i686 $(call tune,core2)

# AMD Elan support
cflags-$(CONFIG_X86_ELAN)	+= -march=i486

# Geode GX1 support
cflags-$(CONFIG_MGEODEGX1)	+= -march=pentium-mmx

# add at the end to overwrite eventual tuning options from earlier
# cpu entries
cflags-$(CONFIG_X86_GENERIC) 	+= $(call tune,generic,$(call tune,i686))