muxcover generates x states

[miradarya]

Version

0.47

On which OS did this happen?

Linux, Windows

Reproduction Steps

I haven't been able to verify the fix for #3591 for some time now. Unfortunately however, commit 822c7b0 breaks muxcover, at least for some non-trivial cases. I currently have a design where muxcover after 822c7b0 generates x states on the S input of several $_MUX8_ cells. There are no x states present in the design before executing muxcover. Reverting muxcover.cc to before 822c7b0 does not generate x states (but still has the cost estimation issue mentioned in #3591). At this point, I cannot provide the actual design that reproduces the issue. I am unsure though, how to create a minimal example.

Expected Behavior

design with correctly connected $_MUX8_ cells

Actual Behavior

design with x states on (at least) S input of $_MUX8_ cells