I posted this to the MLVM list, but I thought it would be interesting here. I'm happy to answer any questions about JRuby's uses of invokedynamic.
Hello friends! Just updating you on the status of JRuby + invokedynamic, for those of you following along. About halfway through this month I did another pass at getting tests passing with invokedynamic enabled, and finally turned on all uses (at the time) of indy in JRuby! Hooray! Last week, I finally enabled Ruby to Java dispatch via invokedynamic for single-arity methods as well. The performance on those calls appears to be about double what it was before...reflection is a harsh mistress. Last night, I added an experimental change to use invokedynamic for looking up Ruby instance variables. Ruby ivars are basically like a Map on every object, so we use various techniques to avoid storing an entire map. My hope is that an indy lookup path will be faster than the non-indy path...but so far, they're about equal. I have not enabled this on master, but it can be enabled by passing -Xinvokedynamic.cache.ivars=true to JRuby or -Djruby.invokedynamic.cache.ivars=true passed to Java. Invokedynamic is being used for the following: * Method dispatches from Ruby to Ruby with fixed-arity target methods that do not require heap frames * Method dispatches from Ruby to Java with fixed-arity target methods * Loads of literals and lazily-allocated runtime constructs * Constant lookups * Math and boolean operations where the right operand is a literal integer or float have special treatment Things are looking very good. Also recently, I modified how JRuby prints out configuration properties. All properties for invokedynamic should now be properly displayed by passing --properties to JRuby. Upcoming work includes getting Ruby methods with variable arity and heap frames to use invokedynamic, as well as Java methods with variable arity. Have fun! - Charlie -- You received this message because you are subscribed to the Google Groups "JVM Languages" group. To post to this group, send email to jvm-languages@googlegroups.com. To unsubscribe from this group, send email to jvm-languages+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/jvm-languages?hl=en.
