Re: [PATCH] x86/vdso: include generic __lshrdi3 in 32-bit vDSO

From: Nick Desaulniers
Date: Mon Mar 18 2019 - 13:09:52 EST


On Fri, Mar 15, 2019 at 3:29 PM Matthias Kaehlcke <mka@xxxxxxxxxxxx> wrote:
> On Fri, Mar 15, 2019 at 02:31:09PM -0700, 'Nick Desaulniers' via Clang Built Linux wrote:
> > Is there a config I can set to reproduce this, in order to help
> > test?
>
> I encountered it with a Chrome OS specific configuration, but a
> defconfig should do.

defconfig selects CONFIG_OPTIMIZE_FOR_PERFORMANCE=y. I needed to
select CONFIG_CC_OPTIMIZE_FOR_SIZE=y to repro. My CI is simply
running defconfigs, which is why I didn't catch this.

> Note that you probably need a development version
> of clang to reproduce this.

Yep. Thanks for the patch.

Tested-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
--
Thanks,
~Nick Desaulniers