Let me preface this by saying performance is complicated, and unfortunately far more..
Let me preface this by saying performance is complicated, and unfortunately far more... religious than you'd expect. A good example of this is the Objective-C community’s old insistence that good performance was incompatible with garbage collection, despite decades of proof otherwise. This post [1] about Swift getting walloped by node.js is fascinating in seeing how a community responds with results that challenge their expectations (“what do you expect, the JS BigInt is optimized and ours isn’t”, “It’s slower, but uses less RAM!”, etc.). As it turns out, questions like GC vs. reference counting, often end up being much more nuanced (and unsatisfactory) than which is simply "faster". You end up with far more unsatisfying conclusions like one is more deterministic but often slower (and as it turns out most UIKit apps aren’t realtime systems). All this to say, it is hard to answer this question in one comment, but to try to sum up my position on this, I believe the performance benefits of Swift were and remain overblown. …
Original discussionThe Swift compiler is slow due to how types are inferred221 source comments · at import