graal

Since Sumatra depends on Graal, it being integrated, means Graal also has to be.

It is my understanding that if Graal proves itself, it will replace C2 (if not C1 as well).

BTW, would Graal really become available as a stock-HotSpot plugin in Java 9 thanks to JEP 243?

BTW, you don't even need Graal to be the default JIT in order to support Sumatra, anyway.

Did you see that they're planning on making Graal a plugin of the standard OpenJDK build in Java 9?

Bigger challenge is how to bootstrap graal itself such that compilation time and thus time to peak perf isn't degraded substantially.

As I understand it, JEP 243 will allow to plug Graal into the standard OpenJDK HotSpot (though at reduced speed), until Graal matures enough to become HotSpot's default compiler.

As already mentioned, Graal is just the JIT compiler, it's not the entire VM.

My point is that Sumatra wouldn't have played a significant role in the decision of when to make Graal HotSpot's default JIT.

Java 9 will even let us use Graal as the optimizing compiler (i.e.

During compilation, Graal interacts with the node and the node gives further instructions.

This can be improved to be CF sensitive, and Graal does that.

It is my understanding that Graal -- one of the two JITs used in the paper -- will be available for use with "stock OpenJDK HotSpot" as a plugin (as opposed to a special HotSpot build), starting in Java 9.

So what Graal will do is let the developer (if the language designer allows), write simple, high-level code, but tell the compiler, "listen, compile however you like, but when you get to this function, talk to me because I have some ideas on how to compile it just right".

Oracle has been investing significant resources in JRuby for some time via the Graal/Truffle research projects.

Is there some kind of vision or plan for how Graal/Truffle fits into the JRuby roadmap?

All this is about to get even better with Truffle/Graal in Java 9.