Re: [PATCH 2/7] Makefile, x86, LLVM: disable unsupported optimization flags

From: Matthias Kaehlcke
Date: Wed Apr 05 2017 - 15:01:42 EST


Hi Masahiro,

El Thu, Apr 06, 2017 at 03:08:26AM +0900 Masahiro Yamada ha dit:

> 2017-03-17 9:15 GMT+09:00 Michael Davidson <md@xxxxxxxxxx>:
> > Unfortunately, while clang generates a warning about these flags
> > being unsupported it still exits with a status of 0 so we have
> > to explicitly disable them instead of just using a cc-option check.
> >
> > Signed-off-by: Michael Davidson <md@xxxxxxxxxx>
>
>
> Instead, does the following work for you?
> https://patchwork.kernel.org/patch/9657285/

Thanks for the pointer, I was about to give this change (or rather its
ancestor) a rework myself :)

> You need to use
> $(call cc-option, ...)
> for -falign-jumps=1 and -falign-loops=1

I can confirm that this works.

Thanks

Matthias