Why not add Inline Caches (IC) for CPython

Hey. I’ve been reading the draft of PEP 836 (JIT Go Brrr) recently, and I’m quite interested in the future performance direction of CPython. However, when I got to the sections about “evolving the tracing frontend to a method-based frontend,” “LLVM dependency,” and “a 2.5-year timeline to achieve 20% performance improvement,” a question arose in my mind: Before investing such massive engineering effort, have we already squeezed out all the “cheap performance” from the current interpreter archi...