# 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_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