A small update for you guys on the different compilers and GGC. I hope it answers some questions you had.
1) What's the deal with GGC and the impact for performance
I'm not involved with GGC and I only hear bits and pieces about it. But from what I've heard the GGC development is going nicely. There is still a lot of work to do, but it is coming. It will probably take another 2-3 months to get it in a functional state. It will decrease the GC pauzes even more and that will be very noticeable in the browser. As for increasing performance, yes it will increase performance, but only by reducing the GC time that happens during benchmarks. That means no increase for SS. For V8 we already identified some places that will definitely benefit from it. BUT the performance atm is not blocked on GGC. For most benchmarks where we are not on par with google chrome, the improvements coming from IonMonkey will be greater than the improvements GGC will bring. (At least that's what I assume from the measurements I did)
2) What's the deal with JaegerMonkey
It will get removed
. Yeah I'm really happy with that. There are some reasons for this. Many optimizations in JaegerMonkey are hacked together, because there is no decent way to do. IonMonkey has a much easier/better design in that regard. Also JaegerMonkey needs to recompile whenever types changes ... That's one of the reasons of our bad performance on SS. Also it looses it's information when we compile IonMonkey, resulting in the performance differences of 10% on some V8 benchmarks. ETA is when the replacement baseline compiler is done and at least as fast as JaegerMonkey.
3) What's the deal with Baseline
Shaping up nicely. The basic design is done and the hardest part are in. That is almost all opcodes get compiled to a basic version. Later on we can improve the generated output by seeing which types flow in. Evilpie, a contributor, has already begon with this, Thanks! But the major focus is nowto fix all the failing tests. Last thing I heard it would take another 2-3 months.
4) What's the deal with IonMonkey
Most faults are now gone and we are fully looking at performance issues. Mostly on the V8 benchmark, a benchmark where we were historically bad at. That has given us already nice gains since October. This focus will continue in the next few months.
