Hi Segher,

> On 5 Oct 2020, at 19:27, Olivier Hainque <hainque@adacore.com> wrote:
> 
> I'll post an updated version, thanks for the comments.

Here's an updated version which passed in-house build & tests
with gcc-10 based toolchains for VxWorks 6.9 & 7.2, and with which
I could build mainline for VxWorks 6.9 including libstdc++ (combined
with a few other patches, orthogonal to what is proposed here and
which I'll post shortly).

Same ChangeLog. Patch hopefully quotable if needed now.

Olivier

2020-10-13  Olivier Hainque  <hainque@adacore.com>

       * config/rs6000/vxworks.h (TARGET_OS_CPP_BUILTINS): Accommodate
       expectations from different versions of VxWorks, for 32 or 64bit
       configurations.