They have committed to including a JIT in 2.2. On Aug 19, 11:42 am, DanH <[email protected]> wrote: > Actually, I haven't seen confirmation that Dalvik even has a JIT, much > less a "reasonably good" one. I know it's been "talked about". > > But I haven't really caught up to the latest yet. > > On Aug 19, 12:54 pm, Amit <[email protected]> wrote: > > > Hi Dan, > > > Thanks for the response > > > > In general, JITed Java code is as fast as or faster than the > > > equivalent native code, if the JIT is reasonably good, and if the > > > specific application can be coded efficiently in Java. > > > I was actually banking on this. I don't know too much of the hairy > > details (am not really a compiler person), but from what I have read > > recent improvements by Google to the Dalvik VM make it *comparable* if > > not equal in performance to native code ... > > > Hate to sound like I'm harping on the same stuff, but then (assuming > > that the JVM/JIT compiler is doing good enough), the memory bottleneck > > still remains. > > > Thanks, > > Amit > > > On Aug 19, 10:11 pm, DanH <[email protected]> wrote: > > > > In general, JITed Java code is as fast as or faster than the > > > equivalent native code, if the JIT is reasonably good, and if the > > > specific application can be coded efficiently in Java. The problem is > > > that some specific data processing patterns are not easy to code > > > efficiently in Java, and I suspect that certain of the bit-bashing > > > algorithms used in image processing fall into this category. > > > > In such cases the most efficient approach is "native Java", but I only > > > know of one JVM (the IBM iSeries "classic" JVM) that permits this, and > > > then only for system code. Otherwise it's a bit of a tradeoff to get > > > the right partitioning between Java and native, since crossing the > > > Java/native boundary tends to be relatively expensive. > > > > On Aug 19, 7:03 am, Fabrizio Giudici <[email protected]> > > > wrote: > > > > > -----BEGIN PGP SIGNED MESSAGE----- > > > > Hash: SHA1 > > > > > On 8/19/10 13:35 , Amit wrote: > > > > > > Now, I know that native code will *not* yield any significant > > > > > performance improvement over Java code > > > > > Well, specifically for image processing this won't be true, for sure > > > > up to 2.1 included (as the bytecode is purely interpreted); in 2.2 we > > > > have JIT, but can't speak as I haven't seen it yet. > > > > > - -- > > > > Fabrizio Giudici - Java Architect, Project Manager > > > > Tidalwave s.a.s. - "We make Java work. Everywhere." > > > > java.net/blog/fabriziogiudici -www.tidalwave.it/people > > > > [email protected] > > > > -----BEGIN PGP SIGNATURE----- > > > > Version: GnuPG/MacGPG2 v2.0.14 (Darwin) > > > > Comment: Using GnuPG with Mozilla -http://enigmail.mozdev.org/ > > > > > iEYEARECAAYFAkxtHakACgkQeDweFqgUGxe83wCfSDP1NEN+TLD0iOCZ/zSvQDRw > > > > I5cAoJOEoC7eREU5KuPU7m93/GDj9VUr > > > > =2ZDf > > > > -----END PGP SIGNATURE----- > >
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