Feeds

Mozilla vows Google 'Crankshaft' riposte

'Nobody puts Monkey in a corner'

Top 5 reasons to deploy VMware with Tegile

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.'" ®

Choosing a cloud hosting partner with confidence

More from The Register

next story
UNIX greybeards threaten Debian fork over systemd plan
'Veteran Unix Admins' fear desktop emphasis is betraying open source
Netscape Navigator - the browser that started it all - turns 20
It was 20 years ago today, Marc Andreeesen taught the band to play
Redmond top man Satya Nadella: 'Microsoft LOVES Linux'
Open-source 'love' fairly runneth over at cloud event
Chrome 38's new HTML tag support makes fatties FIT and SKINNIER
First browser to protect networks' bandwith using official spec
Admins! Never mind POODLE, there're NEW OpenSSL bugs to splat
Four new patches for open-source crypto libraries
Torvalds CONFESSES: 'I'm pretty good at alienating devs'
Admits to 'a metric ****load' of mistakes during work with Linux collaborators
prev story

Whitepapers

Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
Why and how to choose the right cloud vendor
The benefits of cloud-based storage in your processes. Eliminate onsite, disk-based backup and archiving in favor of cloud-based data protection.
Three 1TB solid state scorchers up for grabs
Big SSDs can be expensive but think big and think free because you could be the lucky winner of one of three 1TB Samsung SSD 840 EVO drives that we’re giving away worth over £300 apiece.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
Security for virtualized datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.