Issue with $clog2 of a parameter

[flaviens]

Hi there!
I'm trying to pass the EL2 core through Yosys. sv2v works without error, but yosys is then complaining about $clog2 of a parameter. It seems that the parameter disappears during sv2v, but I'm not very confident about that. I tried a slightly older sv2v version (10-29) and the newest, without it making any difference.

Here is a pickle ready to be consumed by sv2v.
el2_pickle.zip

Generating RTLIL representation for module `$paramod$2bdb596ed0b0d0fd78c36713ac2804f44d511569\el2_lsu_dccm_mem'.
generated/sv2v_out.v:38018: ERROR: Failed to evaluate system function `\$clog2' with non-constant value.        

Could you please have a quick look?
I'm at your disposal, may you have any question.
Thank you very much!
Flavien

[zachjs]

I have an idea what's going on here, but I'll need some time. I intend to take a closer look this weekend.

[zachjs]

The $clog2 was actually unrelated. sv2v saw a pattern field name and thought it referred to a localparam defined further down due some extra indirection. This is closely related to #255. I've added logic to distinguish the typenames in struct patterns in a4639fa. Please let me know if it works for you. The converted output seems right to me, but I now believe you'll run into an unrelated Yosys limitation: YosysHQ/yosys#668.

This test case was very useful. Thank you very much for filing this issue!

[flaviens]

Hi Zach, thank you so much for your reactivity! This indeed seems to resolve the problem! ❤️
As you mentioned, we run into YosysHQ/yosys#668, although for this specific purpose, it is easier to adapt the source code syntax.
Thanks!