I concur with this. Java JITs do a ton of optimizations and all of the effects of exceptions are minimal, second-order things, like keeping something alive a li

I concur with this. Java JITs do a ton of optimizations and all of the effects of exceptions are minimal, second-order things, like keeping something alive a little longer (for deoptimization/debugging). If the compiler has a good notion of hot/cold paths, then a lot of optimizations that you'd be tempted to think up for exceptions fall out naturally from the more general notion, including spilling the likely-never-used-but-alive-for-deopt values onto the stack in the important paths.