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_M386) += -march=i386 14cflags-$(CONFIG_M486) += -march=i486 15cflags-$(CONFIG_M586) += -march=i586 16cflags-$(CONFIG_M586TSC) += -march=i586 17cflags-$(CONFIG_M586MMX) += -march=pentium-mmx 18cflags-$(CONFIG_M686) += -march=i686 19cflags-$(CONFIG_MPENTIUMII) += -march=i686 $(call tune,pentium2) 20cflags-$(CONFIG_MPENTIUMIII) += -march=i686 $(call tune,pentium3) 21cflags-$(CONFIG_MPENTIUMM) += -march=i686 $(call tune,pentium3) 22cflags-$(CONFIG_MPENTIUM4) += -march=i686 $(call tune,pentium4) 23cflags-$(CONFIG_MK6) += -march=k6 24# Please note, that patches that add -march=athlon-xp and friends are pointless. 25# They make zero difference whatsosever to performance at this time. 26cflags-$(CONFIG_MK7) += -march=athlon 27cflags-$(CONFIG_MK8) += $(call cc-option,-march=k8,-march=athlon) 28cflags-$(CONFIG_MCRUSOE) += -march=i686 $(align)-functions=0 $(align)-jumps=0 $(align)-loops=0 29cflags-$(CONFIG_MEFFICEON) += -march=i686 $(call tune,pentium3) $(align)-functions=0 $(align)-jumps=0 $(align)-loops=0 30cflags-$(CONFIG_MWINCHIPC6) += $(call cc-option,-march=winchip-c6,-march=i586) 31cflags-$(CONFIG_MWINCHIP3D) += $(call cc-option,-march=winchip2,-march=i586) 32cflags-$(CONFIG_MCYRIXIII) += $(call cc-option,-march=c3,-march=i486) $(align)-functions=0 $(align)-jumps=0 $(align)-loops=0 33cflags-$(CONFIG_MVIAC3_2) += $(call cc-option,-march=c3-2,-march=i686) 34cflags-$(CONFIG_MVIAC7) += -march=i686 35cflags-$(CONFIG_MCORE2) += -march=i686 $(call tune,core2) 36cflags-$(CONFIG_MATOM) += $(call cc-option,-march=atom,$(call cc-option,-march=core2,-march=i686)) \ 37 $(call cc-option,-mtune=atom,$(call cc-option,-mtune=generic)) 38 39# AMD Elan support 40cflags-$(CONFIG_X86_ELAN) += -march=i486 41 42# Geode GX1 support 43cflags-$(CONFIG_MGEODEGX1) += -march=pentium-mmx 44cflags-$(CONFIG_MGEODE_LX) += $(call cc-option,-march=geode,-march=pentium-mmx) 45# add at the end to overwrite eventual tuning options from earlier 46# cpu entries 47cflags-$(CONFIG_X86_GENERIC) += $(call tune,generic,$(call tune,i686)) 48 49# Work around the pentium-mmx code generator madness of gcc4.4.x which 50# does stack alignment by generating horrible code _before_ the mcount 51# prologue (push %ebp, mov %esp, %ebp) which breaks the function graph 52# tracer assumptions. For i686, generic, core2 this is set by the 53# compiler anyway 54ifeq ($(CONFIG_FUNCTION_GRAPH_TRACER), y) 55ADD_ACCUMULATE_OUTGOING_ARGS := y 56endif 57 58# Work around to a bug with asm goto with first implementations of it 59# in gcc causing gcc to mess up the push and pop of the stack in some 60# uses of asm goto. 61ifeq ($(CONFIG_JUMP_LABEL), y) 62ADD_ACCUMULATE_OUTGOING_ARGS := y 63endif 64 65cflags-$(ADD_ACCUMULATE_OUTGOING_ARGS) += $(call cc-option,-maccumulate-outgoing-args) 66 67# Bug fix for binutils: this option is required in order to keep 68# binutils from generating NOPL instructions against our will. 69ifneq ($(CONFIG_X86_P6_NOP),y) 70cflags-y += $(call cc-option,-Wa$(comma)-mtune=generic32,) 71endif 72