arch/x86/kernel/acpi/Makefile_64 - linux - Git at Google

 obj-y			:= boot.o
 obj-$(CONFIG_ACPI_SLEEP)	+= sleep_64.o wakeup_64.o

 ifneq ($(CONFIG_ACPI_PROCESSOR),)
 obj-y			+= processor.o cstate.o
 endif
	obj-y := boot.o
	obj-$(CONFIG_ACPI_SLEEP) += sleep_64.o wakeup_64.o

	ifneq ($(CONFIG_ACPI_PROCESSOR),)
	obj-y += processor.o cstate.o
	endif