What do you mean by "true fixnums"? ~~ Robert.
Charles Oliver Nutter wrote: > We're always trying to make JRuby faster, and I think we've done a > pretty good job. But a recent contender has shown me some areas we > really need to improve. > > MacRuby recently started to implement their backend compilation on top > of LLVM, and it seems to be paying substantial dividends for > performance. On integer math benchmarks, they're several times faster > than JRuby. On closure-performance benchmarks, they're at least twice as > fast. Most of their performance boost seems to come from a couple > specific optimizations: > > * True fixnums! I don't think we'll ever be able to compete on math > performance until we either get fixnums in the JVM or have enough > information to eliminate constructing them. My early attempts to do this > have involved adding some "long RHS" call paths, which certainly helps. > But we're still constructing too many fixnums, and nothing seems to get > around that fact. Even Java 7 escape analysis combined with my dyncall > inlining work has no effect. > > * Something like alloca. MacRuby generally allocates runtime structures > with alloca, which appears to reduce their overhead substantially. In > our case, closures are allocated with normal heap-based objects, and we > pay the full cost for doing so. If we could reify local variables into a > heap structure lazily, or stand up a scoping structure that only lived > on the stack, we might get closer. > > * Lack of an optimizing compiler framework for JVM. The truth is that > we're expecting too much of the JVM. We need a better compiler framework > that can do some type inference, constant propagation, etc, and be aware > of what bytecode and runtime logic optimizes well. The work Tobias is > starting on ssa-compiler will be important...we need to find a way to > move it along faster. I have a couple books and papers to read so I can > be useful in this regard. > > I'd like to hear what other languages, especially dynamic languages, are > doing to take the next performance steps. I'd also like input on what we > can do to continue improving JRuby, and hopefully improve the state of > dynlangs on JVM at the same time. > > - Charlie > > > > -- ~~ Robert Fischer. Grails Training http://GroovyMag.com/training Smokejumper Consulting http://SmokejumperIT.com Enfranchised Mind Blog http://EnfranchisedMind.com/blog Check out my book, "Grails Persistence with GORM and GSQL"! http://www.smokejumperit.com/redirect.html --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
