Firefox 18 Beta Out With IonMonkey JavaScript Engine

An anonymous reader writes with a quick bite from The Next Web about the latest Firefox beta, this time featuring some under-the-hood improvements: "Mozilla on Monday announced the release of Firefox 18 beta for Windows, Mac, and Linux. You can download it now from Mozilla.org/Firefox/Beta. The biggest addition in this update is significant JavaScript improvements, courtesy of Mozilla's new JavaScript JIT compiler called IonMonkey. The company promises the performance bump should be noticeable whenever Firefox is displaying Web apps, games, and other JavaScript-heavy pages."

Comments

Re:So far

[epyT-R]

javascript was never meant to do the things it's being used for now, that's why sites are so damned slow now.

Re:So far

[NightHwk1]

What sites are so damned slow? It's not the Javascript in most cases, it's the asset loading. The tubes are still the bottleneck on the web.

If anything, Javascript is speeding things up. AJAX content updates without a full page refresh are commonplace now, and there are more and more sites that are mostly client-side, using frameworks like Backbone.

JS Speed is the deciding factor in modern webpages

[detain]

Its good to see the focus of this release being an attempt to increase javascript speed by leaps and bounds. Modern webpages often use JS that goes way beyond anything people did 10 years ago (Jquery for example) and the complexities of what people do with javascript noticably slow down most webpages considerably.

Re:JS Speed is the deciding factor in modern webpa

[madsdyd]

I don't understand why this comment got +5. It is pretty misguided.

The statement:

> I realized, you can't speed up assembly language -- It's a perfectly optimized language, there's nothing under the hood to tweak

makes some limited sense in some contexts (one could argue that the microcode supporting the assembler on the CPU is repeatedly optimized), but none in this. The IonMonkey JIT does essentially optimize the assembler code[*], by rearranging it in various ways to make it faster. E.g. it takes stuff like this (in javascript, as I have not written assembler in years):

for ( var i = 0; i != 10 ; ++ i ) {
    var foo = "bar";
}

and changes it to e.g. this:

for ( var i = 0; i != 10; ++i ) {
}
var foo = "bar";

possibly then this:

var foo = "bar";

This is an optimization and it is performed at assembler level (Again: the above is not meant to be read as JavaScript, but assembler).

The other statement that really sticks out is this:

> A sign of a horribly designed language is that the speed of its implementations can be repeatedly increased "by leaps and bounds"...

This simply highlights that the poster really do not understand the goals behind crossplatform languages, such as Java, Dalvik, JavaScript, lisp, ML, Python, Perl, and so on, or the goals for weakly typed languages.

[*] It works on an abstract representation of the assembler code, but it might as well have been working directly on the assembler, was it not for the fact that this would require it to learn to many assembler variants.