Firefox 4 preview knocks back Jäger shot

Buzzed browser races rivals for JavaScript crown


Mozilla has released preview builds of Firefox 4 that include JägerMonkey, the new JavaScript engine extension designed to outpace rival engines from the likes of Google and Opera.

According to the open source outfit's latest SunSpider JavaScript benchmarks, JägerMonkeyed Firefox still trails all major competitors, but on the V8 benchmark, it has surpassed Microsoft's Internet Explorer 9 preview, and on both test suites, it's steadily gaining ground.

With Firefox 3.5, Mozilla juiced JavaScript performance with a compiler known as TraceMonkey, but not all JavaScript code is suited to Mozilla's "tracing" technique, which works to convert code loops into speedy assembly language. JägerMonkey aims to boost performance when tracing doesn't apply.

JägerMonkey is a method JIT compiler based on the Nitro assembler built for Apple’s open-source WebKit project, the same assembler used by the Google Chrome and Apple Safari browsers. TraceMonkey will continue to convert code loops into assembly code, but when this isn't possible, JägerMonkey will kick in, converting entire methods to assembly code.

Jagermonkey diagram

JägerMonkey borrows the Nitro assembler from WebKit

"While the technology inside TraceMonkey makes it faster than any other engine on certain programs (then and now), it doesn’t help other programs as much. And the web has grown more complex, with more and more JavaScript-intensive demos, apps, and games," reads a blog post from Mozilla man David Mandelin announcing the release of the JägerMonkey preview builds. "And the competition has been getting a lot tougher, with engines that could run fast on bigger and prettier web apps. We knew we needed another major upgrade for Firefox 4.0, to make us fast all around."

Mandelin says the project involved revamping the fundamental value type of Firefox's Javascript engine, which meant updating roughly 20,000 lines of code. He compares this to a "vascular system transplant." The new "whole-method" JIT compiler required about 23,000 lines of code, and it supports x86, x86-64, and ARM with an "almost entirely shared" compiler code base.

Mozilla director of web platform Chris Blizzard has said that Firefox 4's JavaScript performance will be "one generation" ahead of its rivals. But at least for the moment, Mandelin plays down benchmark numbers. "Those aren’t the main goal, but they are a really convenient target for us to aim at," he says. He adds that the new JavaScript engine will be "a little bit faster yet" by the time Firefox 4 officially arrives this fall.

The JägerMonkey preview builds are available for Linux, Windows, and Mac, including 64-bit Linux and 64-bit Mac. ®

Similar topics


Other stories you might like

  • Euro-telcos call on big tech to help pay for their network builds

    Aka 'rebalancing global technology giants and the European digital ecosystem'

    The European Telecommunications Network Operators' Association (ETNO) has published a letter signed by ten telco CEOs that calls for, among other things, Big Tech to pay for their network builds.

    The letter, signed by the CEOs of the Vodafone Group, BT Group, Deutsche Telekom, Telefónica, Orange Group and five more telco leaders, calls for a "renewed effort to rebalance the relationship between global technology giants and the European digital ecosystem".

    "A large and increasing part of network traffic is generated and monetized by Big Tech platforms, but it requires continuous, intensive network investment and planning by the telecommunications sector," the letter states, adding "This model – which enables EU citizens to enjoy the fruits of the digital transformation – can only be sustainable if such platforms also contribute fairly to network costs."

    Continue reading
  • AI-enhanced frog stem cells start to replicate in entirely new ways

    Xenobots scoop up loose cells to make more of themselves. We welcome our new overlords

    In January of 2020, scientists from the University of Vermont announced they had built the first living robots; this week they have published reports that those robots, made from frog cells and called Xenobots, can reproduce and have found a new way to do so.

    The millimetre-sized xenobots are essentially a computer-designed collection of around 3,000 cells. They were created by taking stem cells from frog embryos, scraping them, leaving them to incubate, then cutting them open and sculpting them into specific shapes. After all that action, the cells began to work on their own – auto-repairing when sliced and moving about inside petri dishes.

    With a little design tweak, the creatures could do even more. "With the right design, they will spontaneously self-replicate," said University of Vermont researcher Joshua Bongard, Ph.D. in a canned statement.

    Continue reading
  • Panasonic admits intruders were inside its servers for months

    Spotted the crack after it ended – still not sure what was lost

    Japanese industrial giant Panasonic has admitted it's been popped, and badly.

    A November 26 statement [PDF] from the company admits that its network "was illegally accessed by a third party on November 11, 2021". That date has since been revised – the company now says it became aware of the intrusion on the 11th, but that unknown entities had access to its systems from late June to early November.

    "After detecting the unauthorized access, the company immediately reported the incident to the relevant authorities and implemented security countermeasures, including steps to prevent external access to the network," the statement adds.

    Continue reading

Biting the hand that feeds IT © 1998–2021