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authorAdrian Bunk <bunk@stusta.de>2008-01-30 07:30:39 -0500
committerIngo Molnar <mingo@elte.hu>2008-01-30 07:30:39 -0500
commit8c4385d7f5b77415156c9b900016cc8161d49f17 (patch)
tree6b00697bbb6df59a24ee44a1d5fab5d1894ee5e2
parent1c69524c2e5b83e52a098ebdeb4a8b52169f6a03 (diff)
x86: remove -maccumulate-outgoing-args on 32-bit
Contrary to the comment "newer gccs do it by default", newer gcc versions default to -maccumulate-outgoing-args only with CONFIG_CC_OPTIMIZE_FOR_SIZE=n, and then only with some CPU settings. Measured with an i386 defconfig, gcc 4.2.1 and kernel 2.6.23-rc1 ("orig" is the plain kernel, "changed is with -maccumulate-outgoing-args removed): $ ls -la vmlinux* -rwxrwxr-x 1 bunk bunk 6269713 2007-07-24 22:19 vmlinux.changed -rwxrwxr-x 1 bunk bunk 6425361 2007-07-24 22:19 vmlinux.orig $ size vmlinux.* text data bss dec hex filename 4493465 504108 614400 5611973 55a1c5 vmlinux.changed 4646160 504108 614400 5764668 57f63c vmlinux.orig $ That's a 2.5% size increase that does for sure hurt small systems. If the stack unwinder ever comes back and needs this as indicated in the comment, adding it to the cflags when the user enabled the unwinder should be a better option. [ tglx: arch/x86 adaptation ] Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
-rw-r--r--arch/x86/Makefile_324
1 files changed, 0 insertions, 4 deletions
diff --git a/arch/x86/Makefile_32 b/arch/x86/Makefile_32
index f806ceccff7a..b152db71d5b5 100644
--- a/arch/x86/Makefile_32
+++ b/arch/x86/Makefile_32
@@ -48,10 +48,6 @@ include $(srctree)/arch/x86/Makefile_32.cpu
48# temporary until string.h is fixed 48# temporary until string.h is fixed
49cflags-y += -ffreestanding 49cflags-y += -ffreestanding
50 50
51# this works around some issues with generating unwind tables in older gccs
52# newer gccs do it by default
53cflags-y += -maccumulate-outgoing-args
54
55# Disable unit-at-a-time mode on pre-gcc-4.0 compilers, it makes gcc use 51# Disable unit-at-a-time mode on pre-gcc-4.0 compilers, it makes gcc use
56# a lot more stack due to the lack of sharing of stacklots: 52# a lot more stack due to the lack of sharing of stacklots:
57KBUILD_CFLAGS += $(shell if [ $(call cc-version) -lt 0400 ] ; then echo $(call cc-option,-fno-unit-at-a-time); fi ;) 53KBUILD_CFLAGS += $(shell if [ $(call cc-version) -lt 0400 ] ; then echo $(call cc-option,-fno-unit-at-a-time); fi ;)