By: Bigos (bigos.delete@this.bigos.bigos), February 23, 2021 6:16 am
Room: Moderated Discussions
Wilco (wilco.dijkstra.delete@this.ntlworld.com) on February 23, 2021 4:15 am wrote:
> Bigos (bigos.delete@this.bigos.bigos) on February 23, 2021 3:55 am wrote:
>
> > I don't think Zen 2 supports ERMS.
>
> That's not relevant. It means GLIBC won't use that memcpy implementation (and it shouldn't
> - not because of ERMS, but because rep movsb is slow even on modern x86 cores).
>
> Wilco
It is relevant, because you show the implementation is slow on an architecture which doesn't advertise the feature it is using.
The performance might not be great on Zen 3 or Haswell+ either, but I would like to see data for that.
> Bigos (bigos.delete@this.bigos.bigos) on February 23, 2021 3:55 am wrote:
>
> > I don't think Zen 2 supports ERMS.
>
> That's not relevant. It means GLIBC won't use that memcpy implementation (and it shouldn't
> - not because of ERMS, but because rep movsb is slow even on modern x86 cores).
>
> Wilco
It is relevant, because you show the implementation is slow on an architecture which doesn't advertise the feature it is using.
The performance might not be great on Zen 3 or Haswell+ either, but I would like to see data for that.