Mozilla has just introduced a new JavaScript optimization feature to Firefox 3.1 development code base (Shiretoko) that well enhances JavaScript-based web apps performance by a 2x – 20x fold compared to the Firefox 3.0, according to JavaScript performance tests ran and published by Mozilla’s Brendan Eich.
I’m extremely pleased to announce the launch of TraceMonkey, an evolution of Firefox’s SpiderMonkey JavaScript engine for Firefox 3.1 that uses a new kind of Just-In-Time (JIT) compiler to boost JS performance by an order of magnitude or more.
Here are some of the charts from Brendan’s blog:
Assorted benchmarks
SunSpider micro-benchmarks
However the best way to evaluate it is to see it in action via simple JavaScript image editor that lets you adjust a picture’s contrast and brightness with a couple of sliders created by Mike Schroepfer. By default, TraceMonkey is disabled (as it is still buggy), there is a very noticeable delay while sliding. Turn it on (javascript.options.jit.content = true in about:config) and the thing works like charm, very smoothly.
JavaScript Image Editor
Going into significant detail on how all of this came about, Brendan notes some key points:
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