julia

1829ceea - optimizer: Do not run if we know the function is ConstABI eligible (#51143)

optimizer: Do not run if we know the function is ConstABI eligible (#51143) If we can determine that a function is sufficiently pure and returns a constant, we have special ABI that lets us throw away the code for it and just return the constant. However, we were still going through all the steps of actually computing the code, including running the optimizer on it, compressing it in preparation for caching, etc. We can just stop doing that and bypass the optimizer entirely. The actual change to do this is pretty tiny, but there's some unexpected fallout which this needs to cleanup: 1. Various tests expect code_* queries of things inferred to ConstABI to still return reasonable code. Fix this by manually emitting a ReturnNode at the end of inference if the caller is a reflection function. 2. This kinda wreaks havoc on the EscapeAnalysis tests, which work by using a side-effect of the optimizer, but a lot of the functions are ConstABI eligible, so the optimizer doesn't run any more. Fortunately, I'm in the middle of looking at overhauling EscapeAnalysis, so I'll have some chance to figure out how to change the test system to actually do this properly, rather than exfiltrating side effects. That said, since EscapeAnalysis is not in the default pipeline, I don't think we should hold the perf improvement until that is done. Benchmarked to be about 10% faster locally, but we'll see what nanosoldier thinks. --------- Co-authored-by: Shuhei Kadowaki <40514306+aviatesk@users.noreply.github.com>