1# CPU tuning section - shared with UML. 2# Must change only cflags-y (or [yn]), not CFLAGS! That makes a difference for UML. 3 4#-mtune exists since gcc 3.4 5HAS_MTUNE := $(call cc-option-yn, -mtune=i386) 6ifeq ($(HAS_MTUNE),y) 7tune = $(call cc-option,-mtune=$(1),$(2)) 8else 9tune = $(call cc-option,-mcpu=$(1),$(2)) 10endif 11 12align := $(cc-option-align) 13cflags-$(CONFIG_M486) += -march=i486 14cflags-$(CONFIG_M586) += -march=i586 15cflags-$(CONFIG_M586TSC) += -march=i586 16cflags-$(CONFIG_M586MMX) += -march=pentium-mmx 17cflags-$(CONFIG_M686) += -march=i686 18cflags-$(CONFIG_MPENTIUMII) += -march=i686 $(call tune,pentium2) 19cflags-$(CONFIG_MPENTIUMIII) += -march=i686 $(call tune,pentium3) 20cflags-$(CONFIG_MPENTIUMM) += -march=i686 $(call tune,pentium3) 21cflags-$(CONFIG_MPENTIUM4) += -march=i686 $(call tune,pentium4) 22cflags-$(CONFIG_MK6) += -march=k6 23# Please note, that patches that add -march=athlon-xp and friends are pointless. 24# They make zero difference whatsosever to performance at this time. 25cflags-$(CONFIG_MK7) += -march=athlon 26cflags-$(CONFIG_MK8) += $(call cc-option,-march=k8,-march=athlon) 27cflags-$(CONFIG_MCRUSOE) += -march=i686 $(align)-functions=0 $(align)-jumps=0 $(align)-loops=0 28cflags-$(CONFIG_MEFFICEON) += -march=i686 $(call tune,pentium3) $(align)-functions=0 $(align)-jumps=0 $(align)-loops=0 29cflags-$(CONFIG_MWINCHIPC6) += $(call cc-option,-march=winchip-c6,-march=i586) 30cflags-$(CONFIG_MWINCHIP3D) += $(call cc-option,-march=winchip2,-march=i586) 31cflags-$(CONFIG_MCYRIXIII) += $(call cc-option,-march=c3,-march=i486) $(align)-functions=0 $(align)-jumps=0 $(align)-loops=0 32cflags-$(CONFIG_MVIAC3_2) += $(call cc-option,-march=c3-2,-march=i686) 33cflags-$(CONFIG_MVIAC7) += -march=i686 34cflags-$(CONFIG_MCORE2) += -march=i686 $(call tune,core2) 35cflags-$(CONFIG_MATOM) += $(call cc-option,-march=atom,$(call cc-option,-march=core2,-march=i686)) \ 36 $(call cc-option,-mtune=atom,$(call cc-option,-mtune=generic)) 37 38# AMD Elan support 39cflags-$(CONFIG_MELAN) += -march=i486 40 41# Geode GX1 support 42cflags-$(CONFIG_MGEODEGX1) += -march=pentium-mmx 43cflags-$(CONFIG_MGEODE_LX) += $(call cc-option,-march=geode,-march=pentium-mmx) 44# add at the end to overwrite eventual tuning options from earlier 45# cpu entries 46cflags-$(CONFIG_X86_GENERIC) += $(call tune,generic,$(call tune,i686)) 47 48# Work around the pentium-mmx code generator madness of gcc4.4.x which 49# does stack alignment by generating horrible code _before_ the mcount 50# prologue (push %ebp, mov %esp, %ebp) which breaks the function graph 51# tracer assumptions. For i686, generic, core2 this is set by the 52# compiler anyway 53ifeq ($(CONFIG_FUNCTION_GRAPH_TRACER), y) 54ADD_ACCUMULATE_OUTGOING_ARGS := y 55endif 56 57# Work around to a bug with asm goto with first implementations of it 58# in gcc causing gcc to mess up the push and pop of the stack in some 59# uses of asm goto. 60ifeq ($(CONFIG_JUMP_LABEL), y) 61ADD_ACCUMULATE_OUTGOING_ARGS := y 62endif 63 64cflags-$(ADD_ACCUMULATE_OUTGOING_ARGS) += $(call cc-option,-maccumulate-outgoing-args) 65 66# Bug fix for binutils: this option is required in order to keep 67# binutils from generating NOPL instructions against our will. 68ifneq ($(CONFIG_X86_P6_NOP),y) 69cflags-y += $(call cc-option,-Wa$(comma)-mtune=generic32,) 70endif 71