Zeev, >> Right now it compiles script (php file) at once. >> So yes, our JIT uses some kind of AOT approach, but completely >> transparently for the rest of PHP. > > Just to slightly further clarify - we don't compile the whole codebase at > once, but we keep the existing semantics that every file is independent, may > change independently of other files, and include() may end up load one file > in one flow and another one in another flow. There's isn't any cross-file > optimization. > >> We also tried few different approaches to collect formation about hot >> functions and generate code only for them. >> Unfortunately, this didn't change the picture. > > (again, the picture being no performance gains in common Web apps).
Well, I just want to make one clarification here to your point: there's no performance gains to this AOT approach for common web apps. It's not really fair to judge a true JIT implementation based on this because it lacks crucial runtime information that a real JIT compiler would have (such as input types, values, etc). So it would be left generating generic native code instead of specific code. I just want to point out that the results here aren't really applicable to a JIT approach. And that should be made clear when discussing it. That's not to say there's anything wrong with this approach, nor that there isn't a ton we can learn from it. I think it's a fantastic research effort and plan on digging through it myself. Thank you for open sourcing it. Anthony -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
