Commit 1b21376a authored by Douglas Anderson's avatar Douglas Anderson Committed by Russell King
Browse files

ARM: 7777/1: Avoid extra calls to the C compiler 



Starting up the C compiler can be a slow operation on some systems.
Though these calls don't individually take a lot of time, they add up.
Rearrange the ARM Makefile a bit to avoid extra calls to the compiler
when they can be easily avoided.

When running with the Chrome OS ARM cross compiler
"armv7a-cros-linux-gnueabi-", this shaved .55 seconds (from 5.31
seconds to 4.76 seconds) off an incremental build of the kernel:
  time make -j32 ARCH=arm CROSS_COMPILE=armv7a-cros-linux-gnueabi-

Thanks to Mike Frysinger for the clean trick to make this work.

Signed-off-by: default avatarDoug Anderson <dianders@chromium.org>
Acked-by: default avatarMike Frysinger <vapier@gentoo.org>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 81793bab

arch/arm/Makefile

+31 −25
Original line number Diff line number Diff line
@@ -59,37 +59,43 @@ comma = , 
# Note that GCC does not numerically define an architecture version

# macro, but instead defines a whole series of macros which makes

# testing for a specific architecture or later rather impossible.

arch-$(CONFIG_CPU_32v7)		:=-D__LINUX_ARM_ARCH__=7 $(call cc-option,-march=armv7-a,-march=armv5t -Wa$(comma)-march=armv7-a)

arch-$(CONFIG_CPU_32v6)		:=-D__LINUX_ARM_ARCH__=6 $(call cc-option,-march=armv6,-march=armv5t -Wa$(comma)-march=armv6)

arch-$(CONFIG_CPU_32v7)		=-D__LINUX_ARM_ARCH__=7 $(call cc-option,-march=armv7-a,-march=armv5t -Wa$(comma)-march=armv7-a)

arch-$(CONFIG_CPU_32v6)		=-D__LINUX_ARM_ARCH__=6 $(call cc-option,-march=armv6,-march=armv5t -Wa$(comma)-march=armv6)

# Only override the compiler option if ARMv6. The ARMv6K extensions are

# always available in ARMv7

ifeq ($(CONFIG_CPU_32v6),y)

arch-$(CONFIG_CPU_32v6K)	:=-D__LINUX_ARM_ARCH__=6 $(call cc-option,-march=armv6k,-march=armv5t -Wa$(comma)-march=armv6k)

arch-$(CONFIG_CPU_32v6K)	=-D__LINUX_ARM_ARCH__=6 $(call cc-option,-march=armv6k,-march=armv5t -Wa$(comma)-march=armv6k)

endif

arch-$(CONFIG_CPU_32v5)		:=-D__LINUX_ARM_ARCH__=5 $(call cc-option,-march=armv5te,-march=armv4t)

arch-$(CONFIG_CPU_32v4T)	:=-D__LINUX_ARM_ARCH__=4 -march=armv4t

arch-$(CONFIG_CPU_32v4)		:=-D__LINUX_ARM_ARCH__=4 -march=armv4

arch-$(CONFIG_CPU_32v3)		:=-D__LINUX_ARM_ARCH__=3 -march=armv3

arch-$(CONFIG_CPU_32v5)		=-D__LINUX_ARM_ARCH__=5 $(call cc-option,-march=armv5te,-march=armv4t)

arch-$(CONFIG_CPU_32v4T)	=-D__LINUX_ARM_ARCH__=4 -march=armv4t

arch-$(CONFIG_CPU_32v4)		=-D__LINUX_ARM_ARCH__=4 -march=armv4

arch-$(CONFIG_CPU_32v3)		=-D__LINUX_ARM_ARCH__=3 -march=armv3



# Evaluate arch cc-option calls now

arch-y := $(arch-y)



# This selects how we optimise for the processor.

tune-$(CONFIG_CPU_ARM7TDMI)	:=-mtune=arm7tdmi

tune-$(CONFIG_CPU_ARM720T)	:=-mtune=arm7tdmi

tune-$(CONFIG_CPU_ARM740T)	:=-mtune=arm7tdmi

tune-$(CONFIG_CPU_ARM9TDMI)	:=-mtune=arm9tdmi

tune-$(CONFIG_CPU_ARM940T)	:=-mtune=arm9tdmi

tune-$(CONFIG_CPU_ARM946E)	:=$(call cc-option,-mtune=arm9e,-mtune=arm9tdmi)

tune-$(CONFIG_CPU_ARM920T)	:=-mtune=arm9tdmi

tune-$(CONFIG_CPU_ARM922T)	:=-mtune=arm9tdmi

tune-$(CONFIG_CPU_ARM925T)	:=-mtune=arm9tdmi

tune-$(CONFIG_CPU_ARM926T)	:=-mtune=arm9tdmi

tune-$(CONFIG_CPU_FA526)	:=-mtune=arm9tdmi

tune-$(CONFIG_CPU_SA110)	:=-mtune=strongarm110

tune-$(CONFIG_CPU_SA1100)	:=-mtune=strongarm1100

tune-$(CONFIG_CPU_XSCALE)	:=$(call cc-option,-mtune=xscale,-mtune=strongarm110) -Wa,-mcpu=xscale

tune-$(CONFIG_CPU_XSC3)		:=$(call cc-option,-mtune=xscale,-mtune=strongarm110) -Wa,-mcpu=xscale

tune-$(CONFIG_CPU_FEROCEON)	:=$(call cc-option,-mtune=marvell-f,-mtune=xscale)

tune-$(CONFIG_CPU_V6)		:=$(call cc-option,-mtune=arm1136j-s,-mtune=strongarm)

tune-$(CONFIG_CPU_V6K)		:=$(call cc-option,-mtune=arm1136j-s,-mtune=strongarm)

tune-$(CONFIG_CPU_ARM7TDMI)	=-mtune=arm7tdmi

tune-$(CONFIG_CPU_ARM720T)	=-mtune=arm7tdmi

tune-$(CONFIG_CPU_ARM740T)	=-mtune=arm7tdmi

tune-$(CONFIG_CPU_ARM9TDMI)	=-mtune=arm9tdmi

tune-$(CONFIG_CPU_ARM940T)	=-mtune=arm9tdmi

tune-$(CONFIG_CPU_ARM946E)	=$(call cc-option,-mtune=arm9e,-mtune=arm9tdmi)

tune-$(CONFIG_CPU_ARM920T)	=-mtune=arm9tdmi

tune-$(CONFIG_CPU_ARM922T)	=-mtune=arm9tdmi

tune-$(CONFIG_CPU_ARM925T)	=-mtune=arm9tdmi

tune-$(CONFIG_CPU_ARM926T)	=-mtune=arm9tdmi

tune-$(CONFIG_CPU_FA526)	=-mtune=arm9tdmi

tune-$(CONFIG_CPU_SA110)	=-mtune=strongarm110

tune-$(CONFIG_CPU_SA1100)	=-mtune=strongarm1100

tune-$(CONFIG_CPU_XSCALE)	=$(call cc-option,-mtune=xscale,-mtune=strongarm110) -Wa,-mcpu=xscale

tune-$(CONFIG_CPU_XSC3)		=$(call cc-option,-mtune=xscale,-mtune=strongarm110) -Wa,-mcpu=xscale

tune-$(CONFIG_CPU_FEROCEON)	=$(call cc-option,-mtune=marvell-f,-mtune=xscale)

tune-$(CONFIG_CPU_V6)		=$(call cc-option,-mtune=arm1136j-s,-mtune=strongarm)

tune-$(CONFIG_CPU_V6K)		=$(call cc-option,-mtune=arm1136j-s,-mtune=strongarm)



# Evaluate tune cc-option calls now

tune-y := $(tune-y)



ifeq ($(CONFIG_AEABI),y)

CFLAGS_ABI	:=-mabi=aapcs-linux -mno-thumb-interwork

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