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Comment by ayosec | Hacker News Reader

So, this means that Google will abandon V8? Or Chrome will continue with it?

This change only affects JavaScriptCore, the original WebKit JS engine. (Various iterations of JavaScriptCore have been promoted as "Squirrelfish" and "Squirrelfish Extreme" and marketed by Apple as "Nitro", so the nomenclature around this engine is a bit confusing.)

Chrome uses V8 instead of JavaScriptCore, and I don't think anything would make them change, since having their own VM is such a large asset for Google (for example, they can use V8 to promote Dart).

JavaScriptCore actually has several JITs. There was the simple JIT that translates JS bytecode to machine code (I think it's called "method JIT"). There's a more advanced JIT that does data flow analysis. This is fairly new; I think it shipped last year in 64-bit Safari.

This new development is about improving performance on code that may not need to be JIT-compiled. Instead of always going to the JIT, they now use a fast interpreter (called LLInt), and only do the native compilation if a code path is deemed hot.

JavaScriptCore is used by Safari, iOS and Mac OS. My guess is that Google will focus on speeding up V8 rather than adopt JSC, but that's just a hunch.

HP just released the source code for their Isis browser for webOS on GitHub and their comments about it all trumpet its use of Javascriptcore (and QtWebKit). They appear to be using code from around r104935 and it's likely they'll want to pull in the LLInt/three-tier VM.

It's newer than anything they've shipped (actually just about everything is, which is a nice change of pace) and we're all waiting like kids on a sugar buzz for the HP-supported effort by the homebrew community to get all the new pieces out through Preware. I will be amused if this hits webOS as an official release before any of the other tablet OSes, but HP seems to be taking the Dadaist approach to the platform.

http://isis-project.org/projects.html https://github.com/isis-project/ https://github.com/isis-project/WebKit/commit/3c619797d896fd...

As stated in the commit logs, this doesn't improve performance on any of the relevant benchmarks, and V8 is still generally king of those (although V8 has been losing to SpiderMonkey on SunSpider for some time now).

I wish Apple would make some new benchmarks, if this interesting new improvement in JSC makes it faster in general but not on the 3 major benchmarks.

If those benchmarks are missing something important, we need better ones.

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