Kernel doesn't use SSE2, so it doesn't need 16 byte alignment. Also
the stack can be already unaligned so letting the compiler align
is useless. This may make some stack frames smaller.
Only works with very recent gcc 4.3
Signed-off-by: Andi Kleen <[EMAIL PROTECTED]>
---
arch/x86_64/Makefile | 2 ++
1 file changed, 2 insertions(+)
Index: linux/arch/x86_64/Makefile
===================================================================
--- linux.orig/arch/x86_64/Makefile
+++ linux/arch/x86_64/Makefile
@@ -49,6 +49,8 @@ CFLAGS += $(call cc-option,-mno-sse -mno
# newer gccs do it by default
CFLAGS += -maccumulate-outgoing-args
+CFLAGS += $(call cc-option,-mpreferred-stack-boundary=3)
+
# do binutils support CFI?
CFLAGS += $(call as-instr,.cfi_startproc\n.cfi_rel_offset
rsp${comma}0\n.cfi_endproc,-DCONFIG_AS_CFI=1,)
AFLAGS += $(call as-instr,.cfi_startproc\n.cfi_rel_offset
rsp${comma}0\n.cfi_endproc,-DCONFIG_AS_CFI=1,)
-
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