Stepping back from this just a little...
Potential OpenJDK contributors wonder whether, all other things being equal, they should choose construction A because it is faster than construction B. And they'd like a better answer than "it's complicated". Usually, the answer IS complicated, so it's hard to know where to start. I suppose one way is to recommend study of or courses in compilers, systems software, computer architecture, and algorithm design to provide a conceptual basis for dealing with virtual machine infrastructures, and then to study OpenJDK source and try performance experiments to see how they apply or are extended. That's not a very satisfying answer either. In the present case, I'm with Martin about short-circuiting this with a simple approximate answer: Rather than flip a coin choosing between solutions A and B, pick the one with smaller bytecode. This has a decent enough correlation with actual performance factors to better than chance. And even if the effects are small, sometimes the only path to making things substantially faster is a few percent at a time. -Doug
