From cca4e4aec1fe52e5ecd15e3cebdbb36e2f254220 Mon Sep 17 00:00:00 2001
From: Wolfgang Denk <wd@denx.de>
Date: Tue, 1 Nov 2011 20:54:02 +0000
Subject: Reduce build times

U-Boot Makefiles contain a number of tests for compiler features etc.
which so far are executed again and again.  On some architectures
(especially ARM) this results in a large number of calls to gcc.

This patch makes sure to run such tests only once, thus largely
reducing the number of "execve" system calls.

Example: number of "execve" system calls for building the "P2020DS"
(Power Architecture) and "qong" (ARM) boards, measured as:
	-> strace -f -e trace=execve -o /tmp/foo ./MAKEALL <board>
	-> grep execve /tmp/foo | wc -l

	Before: After:	Reduction:
==================================
P2020DS 20555	15205	-26%
qong	31692	14490	-54%

As a result, built times are significantly reduced, typically by
30...50%.

Signed-off-by: Wolfgang Denk <wd@denx.de>
Cc: Andy Fleming <afleming@gmail.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Albert Aribaud <albert.aribaud@free.fr>
cc: Graeme Russ <graeme.russ@gmail.com>
cc: Mike Frysinger <vapier@gentoo.org>
Tested-by: Graeme Russ <graeme.russ@gmail.com>
Tested-by: Matthias Weisser <weisserm@arcor.de>
Tested-by: Sanjeev Premi <premi@ti.com>
Tested-by: Simon Glass <sjg@chromium.org>
Tested-by: Macpaul Lin <macpaul@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
---
 arch/x86/config.mk | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

(limited to 'arch/x86')

diff --git a/arch/x86/config.mk b/arch/x86/config.mk
index ee23c9f..fe9083f 100644
--- a/arch/x86/config.mk
+++ b/arch/x86/config.mk
@@ -27,10 +27,12 @@ PLATFORM_CPPFLAGS += -fno-strict-aliasing
 PLATFORM_CPPFLAGS += -Wstrict-prototypes
 PLATFORM_CPPFLAGS += -mregparm=3
 PLATFORM_CPPFLAGS += -fomit-frame-pointer
-PLATFORM_CPPFLAGS += $(call cc-option, -ffreestanding)
-PLATFORM_CPPFLAGS += $(call cc-option, -fno-toplevel-reorder,  $(call cc-option, -fno-unit-at-a-time))
-PLATFORM_CPPFLAGS += $(call cc-option, -fno-stack-protector)
-PLATFORM_CPPFLAGS += $(call cc-option, -mpreferred-stack-boundary=2)
+PF_CPPFLAGS_X86   := $(call cc-option, -ffreestanding) \
+		     $(call cc-option, -fno-toplevel-reorder, \
+		       $(call cc-option, -fno-unit-at-a-time)) \
+		     $(call cc-option, -fno-stack-protector) \
+		     $(call cc-option, -mpreferred-stack-boundary=2)
+PLATFORM_CPPFLAGS += $(PF_CPPFLAGS_X86)
 PLATFORM_CPPFLAGS += -fno-dwarf2-cfi-asm
 PLATFORM_CPPFLAGS += -DREALMODE_BASE=0x7c0
 
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