I'd call it not terribly slow. IIRC it didn't hit 100k lines on an M2, while I saw over two million on my own compiler (I used multiple instances of tcc since I didn't want to deal with implementing debug info on mac)
I don't remember, I grabbed a project that I can't remember the name of and compiled something else first to warm up the compiler then compile the project. I tried several times and it seemed to be consistently < 100K
