jdk

> I had really high hopes for the Java AOT stuff but it seemed to stall (maybe I missed something). Project Leyden [1] aims to standardise AOT for the Java Platform. It is planned to start sometime in the new year. We will most likely end up with two implementations of it. One is GraalVM's native image which will most likely need to make some changes in order to follow the specification. And another implementation will likely be one that is based on HotSpot's C2 compiler [2][3]. [1] https://www.infoq.com/news/2020/05/java-leyden/ [2] https://github.com/openjdk/jdk/pull/960#issuecomment-7220230... [3] https://cl4es.github.io/2020/12/06/Towards-OpenJDK-17.html

Still does. Example: https://docs.oracle.com/en/java/javase/11/docs/api/index.htm... https://github.com/openjdk/jdk/blob/master/src/java.base/sha... I think Gophers borrowed the idea of generating docs from header/source comment from Java. Java itself spec'd it in 1996. Where did Gosling and friends got the idea, I don't know. It may have precedents either in Sun's other languages or possibly an earlier precedent. Some relatively minor differences: In Go, documentation is externalized IFF top level code (function, type, var defs and declarations) immediately follows a comment line. In Java comments have two forms. The comment form using two asterisks is externalized. In Go comments (iirc) support some very basic text styling (of the generated doc). In Java externalized comments can use a basic set of markup ala HTML. This includes comment

https://github.com/openjdk/jdk/graphs/contributors How interesting, more and more activity? year by year

HotSpot definitely uses five tiers (including the interpreter, so same as JSC). https://github.com/openjdk/jdk/blob/0aefe6f20ae719c9793c790d... I'll give you that levels 1-3 use the same IR, but that says more about the generality of the C1 IR than JSC being more advanced for using different IRs IMO.

But Java doesn't do stream fusion as you're describing. It does conventional inlining and combining loop bodies, which can in some trivial cases achieve the same effect, but these are techniques you'd find in any compiler or even an 80s text book - they didn't come from Haskell. Here's the limitation of Java's 'fusion' - you'll notice there's no pass to do this in Hotspot - it just happens due to the inlining and GCM passes. https://github.com/openjdk/jdk/blob/883a4f65b9b1533c8a51d156... And here's a paper on trying to add actual Fusion to Java, which they wouldn't be doing if Java had it already. https://dl.acm.org/doi/pdf/10.1145/3355378.3355386?download=...