Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Ahead-of-Time Compilation

bugs.openjdk.java.net

Post reply on HN
Print view View original

1–10 of 95 posts

Re: Ahead-of-Time Compilation

#2

Post by taspeotis »

I can't see anywhere in the linked issue that indicates AOT compilation is coming to Java 9, or even coming at all. The issue demonstrates nothing more than an intent to bring it to OpenJDK, and the issue seems to be very nascent? It was only created a fortnight ago.

Lest the title is changed:

    AOT compilation is coming to Java 9 (java.net)
    18 points by hittaruki 37 minutes ago

Re: Ahead-of-Time Compilation

#4

Post by avbor »

I'm not familiar enough with compilers, but why would an ahead of time compiler perform worse than a just in time compiler in a static language? I think I'd understand if it was a dynamic language, because you can't know the types for sure until you start running the program, but are similar issues present for Java?

Re: Ahead-of-Time Compilation

#5

Post by chc »

taspeotis wrote: post #2

I can't see anywhere in the linked issue that indicates AOT compilation is coming to Java 9, or even coming at all. The issue demonstrates nothing more than an intent to bring it to OpenJDK, and the issue seems to be very nascent? It was only created a fortnight ago. Lest the title is changed: AOT compilation is coming to Java 9 (java.net) 18 points by hittaruki 37 minutes ago

The person who created this ticket is an Oracle employee, not some random Joe, so it seems like a reasonable guess that it's something Oracle is planning.

Re: Ahead-of-Time Compilation

#6

Post by Scarbutt »

avbor wrote: post #4

I'm not familiar enough with compilers, but why would an ahead of time compiler perform worse than a just in time compiler in a static language? I think I'd understand if it was a dynamic language, because you can't know the types for sure until you start running the program, but are similar issues present for Java?

A JIT can use information from runtime for optimizations, you pay a cost in startup time. Being worse or better depends on the workloads and implementations.

Re: Ahead-of-Time Compilation

#8

Post by yuriks »

avbor wrote: post #4

I'm not familiar enough with compilers, but why would an ahead of time compiler perform worse than a just in time compiler in a static language? I think I'd understand if it was a dynamic language, because you can't know the types for sure until you start running the program, but are similar issues present for Java?

Yes, Java code relies a lot on devirtualization to get good performance. This is because the language allows every function to be virtual by default. The flip-side is that this make coding styles that make heavy usage of interfaces (arguably good for testing, interoperability, decoupling, etc.) effectively "free" compared to ones using concrete classes.

Re: Ahead-of-Time Compilation

#9

Post by Cyph0n »

Assuming this comes in Java 9, and compilation of code other `java.base` is possible, will this make Java a more solid competitor to Go? I guess it partly depends on how much they optimize the compiled binary size. Go does a really good job at static compilation, so it will be tough to compete.
Post reply on HN