[PATCH 4.4 13/70] kbuild: use -Oz instead of -Os when using clang

Greg Kroah-Hartman
2018-11-26T10:55:30Z

From: Behan Webster <behanw@converseincode.com>

commit 6748cb3c299de1ffbe56733647b01dbcc398c419 upstream.

This generates smaller resulting object code when compiled with clang.

Signed-off-by: Behan Webster <behanw@converseincode.com>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
[nc: Adjust context due to lack of commit a76bcf557ef4 in linux-4.4.y]
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
Makefile | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/Makefile
+++ b/Makefile
@@ -628,7 +628,7 @@ KBUILD_CFLAGS += $(call cc-disable-warni
KBUILD_CFLAGS += $(call cc-disable-warning, attribute-alias)

ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
-KBUILD_CFLAGS += -Os
+KBUILD_CFLAGS += $(call cc-option,-Oz,-Os)
else
ifdef CONFIG_PROFILE_ALL_BRANCHES
KBUILD_CFLAGS += -O2