Feeds

Mozilla vows Google 'Crankshaft' riposte

'Nobody puts Monkey in a corner'

Secure remote control for conventional and virtual desktops

Mozilla has vowed not to get "left behind" by Google's latest JavaScript engine, codenamed Crankshaft.

With a blog post on Wednesday, Mozilla's David Mandelin mused on Craftshaft's "adaptive compilation" design and said that the Mozilla JavaScript team and developer community "definitely have the skills and resources to enhance" Firefox's JavaScript engine in ways that match Google's work, and he indicated that this will begin after the release of Firefox 4, due early next year.

Today, at the annual Add-on-Con browser conference in Mountain View, California, Mozilla director of products Jay Sullivan told us that the open source outfit sees Crankshaft as yet another example of the major browser vendors pushing each other to improve JavaScript speed. "It's good. At the highest order, the competition continues," he said, after pointing us to Mandelin's blog post.

Mandelin compares Crankshaft to Firefox's existing TraceMonkey JavaScript engine extension. "I have to point out that run-time type specialization for JavaScript was pioneered by Mozilla’s TraceMonkey project," he said. But he also points out that Crankshaft takes the technique several steps further.

Crankshaft consists of four components. There's a base compiler as well as a run-time profiler that identifies hot code – code that's frequently used. Then an optimizing compiler recompiles the hot code to offer such optimizations as loop-invariant code motion, linear-scan register allocation, and inlining. Plus, Google's V8 team has included "deoptimization support", which identifies cases where the optimizing compiler has over-promised on speed improvements. In this case, the engine falls back on the base compiler.

"Crankshaft introduces an optimizing compiler that does complex optimizations, such as register allocation and loop-invariant code motion," as Mozilla's David Mandelin sees it. "These optimizations take time, so they would make startup slow if that was the only compiler. But Crankshaft also has a base compiler that starts fast but doesn’t optimize very much: probably less than the V8 compiler, in fact. Only if the code is predicted to run many times will it be compiled with full optimization."

With TraceMonkey, Mandelin says, Firefox's engine does something similar. But Crankshaft goes further. Unlike Crankshaft, he says, TraceMonkey just records a trace once – a trace being a code loop that gets reused. Crankshaft, it seems, profiles code repeatedly. It also seems that Crankshaft optimizes entire methods rather than just traces. And it uses inline caching.

"Plenty to do after Firefox 4 comes out," Mandelin said . "In the words of [fellow Mozilla developer] David Anderson, 'The game’s back on.'" ®

Boost IT visibility and business value

More from The Register

next story
'Stop dissing Google or quit': OK, I quit, says Code Club co-founder
And now a message from our sponsors: 'STFU or else'
Why has the web gone to hell? Market chaos and HUMAN NATURE
Tim Berners-Lee isn't happy, but we should be
Microsoft boots 1,500 dodgy apps from the Windows Store
DEVELOPERS! DEVELOPERS! DEVELOPERS! Naughty, misleading developers!
Mozilla's 'Tiles' ads debut in new Firefox nightlies
You can try turning them off and on again
Apple promises to lift Curse of the Drained iPhone 5 Battery
Have you tried turning it off and...? Never mind, here's a replacement
Uber, Lyft and cutting corners: The true face of the Sharing Economy
Casual labour and tired ideas = not really web-tastic
Linux turns 23 and Linus Torvalds celebrates as only he can
No, not with swearing, but by controlling the release cycle
prev story

Whitepapers

Top 10 endpoint backup mistakes
Avoid the ten endpoint backup mistakes to ensure that your critical corporate data is protected and end user productivity is improved.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Backing up distributed data
Eliminating the redundant use of bandwidth and storage capacity and application consolidation in the modern data center.
The essential guide to IT transformation
ServiceNow discusses three IT transformations that can help CIOs automate IT services to transform IT and the enterprise
Next gen security for virtualised datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.