Free Electrons

Embedded Linux Experts

# 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_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_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 $(call tune,core2)
cflags-$(CONFIG_MATOM)		+= $(call cc-option,-march=atom,$(call cc-option,-march=core2,-march=i686)) \
	$(call cc-option,-mtune=atom,$(call cc-option,-mtune=generic))

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

# Geode GX1 support
cflags-$(CONFIG_MGEODEGX1)	+= -march=pentium-mmx
cflags-$(CONFIG_MGEODE_LX)	+= $(call cc-option,-march=geode,-march=pentium-mmx)
# add at the end to overwrite eventual tuning options from earlier
# cpu entries
cflags-$(CONFIG_X86_GENERIC) 	+= $(call tune,generic,$(call tune,i686))

# Work around the pentium-mmx code generator madness of gcc4.4.x which
# does stack alignment by generating horrible code _before_ the mcount
# prologue (push %ebp, mov %esp, %ebp) which breaks the function graph
# tracer assumptions. For i686, generic, core2 this is set by the
# compiler anyway
ifeq ($(CONFIG_FUNCTION_GRAPH_TRACER), y)
ADD_ACCUMULATE_OUTGOING_ARGS := y
endif

# Work around to a bug with asm goto with first implementations of it
# in gcc causing gcc to mess up the push and pop of the stack in some
# uses of asm goto.
ifeq ($(CONFIG_JUMP_LABEL), y)
ADD_ACCUMULATE_OUTGOING_ARGS := y
endif

cflags-$(ADD_ACCUMULATE_OUTGOING_ARGS) += $(call cc-option,-maccumulate-outgoing-args)

# Bug fix for binutils: this option is required in order to keep
# binutils from generating NOPL instructions against our will.
ifneq ($(CONFIG_X86_P6_NOP),y)
cflags-y			+= $(call cc-option,-Wa$(comma)-mtune=generic32,)
endif