Thanks for writing the article, btw. I didn't have a chance to go through the whole thing yet.

Did you have a chance to study Graal's IR? It is a hybrid between sea of nodes and CFG; it can contain some "fixed" nodes that can be wired into basic blocks. It can also be relaxed and have nearly everything floating.

TurboFan's IR was very close to C2, but it had even more things that could float. E.g. a pure operation could be lowered to a subgraph with internal control. TurboFan's schedule could move entire floating control islands and attach them to the main CFG skeleton, or remove them entirely.

I'm working on a new IR and I'll be able to share more soon.

Thanks! I haven't studied Graal's IR in detail, no. I'll add it to my reading list...