Re: [PATCH] kbuild: use -Oz instead of -Os when using clang

From: Masahiro Yamada
Date: Thu Mar 30 2017 - 12:03:35 EST


2017-03-28 10:19 GMT+09:00 Matthias Kaehlcke <mka@xxxxxxxxxxxx>:
> This generates smaller resulting object code when compiled with clang.
>
> Signed-off-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>
> ---
> Makefile | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/Makefile b/Makefile
> index b2faa9319372..66bcdbf58371 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -638,7 +638,8 @@ KBUILD_CFLAGS += $(call cc-option,-fdata-sections,)
> endif
>
> ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
> -KBUILD_CFLAGS += -Os $(call cc-disable-warning,maybe-uninitialized,)
> +KBUILD_CFLAGS += $(call cc-option,-Oz,-Os)
> +KBUILD_CFLAGS += $(call cc-disable-warning,maybe-uninitialized,)
> else
> ifdef CONFIG_PROFILE_ALL_BRANCHES
> KBUILD_CFLAGS += -O2 $(call cc-disable-warning,maybe-uninitialized,)
> --
> 2.12.2.564.g063fe858b8-goog
>



This is the same as the following commit in LLVMLinux
except Author/Signed-off-by.

Who should the authorship really belong to?



commit 186e62808239c603bfa308d5ea994a10d67bb409
Author: Behan Webster <behanw@xxxxxxxxxxxxxxxxxx>
Date: Thu Oct 16 14:28:54 2014 +0200

LLVMLinux: use -Oz instead of -Os when using clang

This generates smaller resulting object code when compiled with clang.

Signed-off-by: Behan Webster <behanw@xxxxxxxxxxxxxxxxxx>


--
Best Regards
Masahiro Yamada