There are claims that ARM's "Jazelle RCT"[1] technology could improve JIT (and not limited to Java). Anyone know if that's just marketing or if there could be worthwhile speedups from this on more recent cores?
IMHO Jazelle and ThumbEE are just marketing gimmicks.
Jazelle was (is?) half-proprietary and is only useful for a really stupid Java bytecode interpreter. Nowadays, Java is JIT-compiled with much better performance.
And ThumbEE came way too late for it to be useful. It requires setup/teardown, doesn't work well with existing code and adds several other complications. It has very few features that may be of use for any VM that has already undergone some basic optimizations.
Believe me, you don't want to waste your time with this.
[1]: http://wiki.tiprocessors.com/index.php/Cortex-A8_Features#Ja...