[libre-riscv-dev] daily kan-ban update 09jul2020

[Jacob Lifshay]

On Thu, Jul 9, 2020 at 7:10 PM Luke Kenneth Casson Leighton
<lkcl at lkcl.net> wrote:
>
> On Friday, July 10, 2020, Jacob Lifshay <programmerjake at gmail.com> wrote:
>
> > today:
> > attended the OpenPower virtual coffee meeting
> > Luke found a bug in the div pipeline, I was able to reproduce it, but
> > the VCD file nmigen produced was utterly useless -- nearly everything
> > is set to 0. Luke (or someone else), I need help here.
>
>
>  i got that too, gtkwave is known to not always display everything
> correctly.

I checked with a completely independent vcd reader and gtkwave is not
at fault this time. nmigen really did write a messed up file.

The vcd reader I used is: https://github.com/sgpthomas/vcdump/pull/1

> honestly if we spend much more time on this it's time instead to convert
> microwatt DIV FSM to nmigen.

Yeah, though with the way that nmigen and/or the pipeline is messed
up, we're highly likely to run into this problem on any new code too.

We need to figure this out.

Jacob