-ifneq ($(CONFIG_GPROF),y)
-ARCH_CFLAGS += -DUM_FASTCALL
-endif
+# First of all, tune CFLAGS for the specific CPU. This actually sets cflags-y.
+include $(srctree)/arch/i386/Makefile.cpu
+
+# prevent gcc from keeping the stack 16 byte aligned. Taken from i386.
+cflags-y += $(call cc-option,-mpreferred-stack-boundary=2)
+
+CFLAGS += $(cflags-y)
+USER_CFLAGS += $(cflags-y)