[Libre-soc-dev] pysvp64asm: opcode setvli not supported

Lauri Kasanen cand at gmx.com
Wed Jun 16 13:19:39 BST 2021

On Wed, 16 Jun 2021 11:53:03 +0100
Luke Kenneth Casson Leighton <lkcl at lkcl.net> wrote:

> how the heck are we going to track this down? can't run qemu
> like i did last time because qemu doesn't support SVP64.
> can't do a direct comparison because the code's different.
> i know, how about this: print out the results of any fmuls and
> fsubs... err no that's not going to work either, there's fmadds
> in here.  the order will be different.

Yes, you can print out each step in the C ver. If the issue turns out
to be in the /mr, then just more granular prints of everything.

The SV matches the C.

> hey, why is the memcpy missing?
>     /* copy to avoid wrap */
>     memcpy(synth_buf + 512, synth_buf, 32 * sizeof(*synth_buf));
> looked at the c code, honestly it doesn't look useful, the macros
> reach juuust the end (no overlap).  oh well.

I wondered about that as well. It turns out it was useful in some
pre-git history in the C ver, and on a quick look is useful in some of
the vectorized versions (they go over).

- Lauri

More information about the Libre-soc-dev mailing list