Java and JIT Compilers (2)
l The Java gPortability Mythh
Write once, debug everywhere
l Optimizations not gPortableh
traditional optimizations
object-oriented optimization (CHA + inlining)
l JIT itself non-portable
hard to retarget (e.g., JIT on VPP)
l Difficult to Customize
E.g., Embedded apps ® Need Memory Efficiency
l Lack of gPerformance Portabilityh
Optimizations may not work
l What do we do? ® Use Reflection