3 ms·
There have been a few runs at this problem. I've wondered for ages why it didn't pick up steam because surely you could get some great performance benefits from
by richardw 17y ago
There have been a few runs at this problem. I've wondered for ages why it didn't pick up steam because surely you could get some great performance benefits from it. Any ideas?
See http://en.wikipedia.org/wiki/Java_processor http://en.wikipedia.org/wiki/Java_processor
- richardw 17y agoAlso, Transmeta used to have a processor with configurable instructions so you could get it to mimic a given machine. Why, why why did they not make a JVM instead of trying to compete with Intel on their home ground?
- akeefer 17y agoAzul systems (http://www.azulsystems.com/ http://www.azulsystems.com/) has a special-purpose Java processor, and they do indeed get some impressive speed benefits from it. For example, having single-instruction write barriers in hardware allows them to have nearly-pauseless garbage collection on gigantic heaps.
- bokchoi 17y agoHere's an excellent google tech talk by Cliff Click of Azul talking about their hardware. Among the firehose of information in that talk, he mentions that the hardware guys wanted to add directly execute JVM bytecode. He told them not to bother since he could JIT it better and they wouldn't be able to support all the bytecodes anyway. I'd love to know more about why that is. http://www.youtube.com/watch?v=5uljtqyBLxI#t=20m00s http://www.youtube.com/watch?v=5uljtqyBLxI#t=20m00s
- pmjordan 17y agoJITing means you can do dynamic optimisations, e.g. predicting vtable dispatches. Doing this in hardware is tricky.
- sketerpot 17y agoMany of the ARM processor cores have hardware support for the most common Java bytecode operations; that's the "Jazelle" extension that others have been mentioning. (The less common operations are left to software, to keep silicon overhead low.)