What are your thoughts on this PR? I could back out the unrelated formatting changes in utils.h, if so desired.

OK, I got rid of the needless formatting changes in kernel/utils.h. PTAL.

It looks like the test latches.ys in the xilinx directory is failing. Investigating.

Fixed. BTW: I realized that this code is somewhat brittle, since the sort order in map and set for some uses of TopoSort depends on the sort order of pointers. This is generally a bad code smell, since it tends to make code non-deterministic.

OK, It finally passed. :-) PTAL.

Trimmed a little fat off my implementation of node(). This speeds the overall topological sorting up by another 10% in my case.

In case you're wondering what's blocking this and #3975, I'd like somebody else to look over and approve it before I merge it, because I'm unfamiliar with the RTLIL internals; perhaps @mmicko?

In case you're wondering what's blocking this and #3975, I'd like somebody else to look over and approve it before I merge it, because I'm unfamiliar with the RTLIL internals; perhaps @mmicko?

Yeah, no worries. It's always good to have more eyes on it.

@Ravenslofty any updates from today's meeting?

We could opt for a non-recursive algorithm (a code example I have at hand), but that might not be producing the sort order code users expect, especially if they supply the C template argument.

Thanks! Yeah, I've sometimes written it non-recursively, but in the profile it doesn't look like the recursion is a problem. One potential issue for large graphs is max allowed stack size, of course.