A two-tier JIT. Interesting to see tiered JIT compilation catch on the way it has. I seem to remember a few years ago reading that the Java HotSpot team had given up on tiered JIT compilation as being not worthwhile.
How far we've come. A whirlwind tour of todays JITs (apologies for the million links):
How far we've come. A whirlwind tour of todays JITs (apologies for the million links):
.Net Core seems not to use tiered compilation. It never interprets the IR; everything is run through the same JIT compiler. https://github.com/dotnet/coreclr/issues/4331
HotSpot uses three tiers these days (counting direct interpretation as a tier) - https://docs.oracle.com/javase/8/docs/technotes/guides/vm/pe...
JavaScriptCore/Nitro seems to use four - https://webkit.org/blog/3362/introducing-the-webkit-ftl-jit/
Edge's Chakra engine has two - https://blogs.msdn.microsoft.com/ie/2014/10/09/announcing-ke...
V8 seems to use two - https://v8project.blogspot.co.uk/2017/05/launching-ignition-...
Firefox's SpiderMonkey JS engine uses two - https://developer.mozilla.org/en-US/docs/Mozilla/Projects/Sp...