Based on a patch of Behan Webster (see [1]). CLANG (here: v3.7) requires '-Oz' as OptLevel to be set.
A Linux v4.3-rc1 kernel built fine with CONFIG_CC_OPTIMIZE_FOR_SIZE=y and boots on bare metal. This is a Ubuntu/precise AMD64 system. Tested against Linux v4.3-rc1 and a refreshed llvmlinux patchset. [1] http://git.linuxfoundation.org/?p=llvmlinux.git;a=blob;f=arch/all/patches/smaller.patch CC: Behan Webster <beh...@converseincode.com> --- Makefile | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/Makefile b/Makefile index 4249441e535d..a57fb6b39ed7 100644 --- a/Makefile +++ b/Makefile @@ -622,7 +622,8 @@ KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks,) 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 KBUILD_CFLAGS += -O2 endif -- 2.5.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
