lkml.org 
[lkml]   [2007]   [Sep]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] [20/45] x86_64: Use 8 byte stack alignment when possible
Date

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 <ak@suse.de>

---
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,)
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
\
 
 \ /
  Last update: 2007-09-21 22:55    [W:0.587 / U:0.060 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site