Smaller bars are better.
Update: The previous graphs came out unintentionally misleading as I tried to resize them to fit my blog. Corrected (thanks Hasan), click to see it full size.
Wow.
I compared WebKit’s new SquirrelFish bytecode JavaScript interpreter against Tamarin, the JIT JavaScript engine currently in Flash 9 and in development for Firefox.
On the SunSpider JavaScript benchmark, SquirrelFish is at least 1.9 times faster than Tamarin with tracing turned on; 1.8 times faster than vanilla Tamarin, the same engine used in Flash 9. When you add type annotations to Tamarin (SquirrelFish doesn’t support them), Tamarin gets a little faster, but is still slower than SquirrelFish on these benchmarks.
Keep in mind, SquirrelFish’s reported times include source compilation, while Tamarin is executing pre-compiled bytecode outside the test.
First Impressions
- I can imagine the “performance per watt” power consumption for SquirrelFish is also much lower. Good for my iPhone’s battery life.
- I think I’m wrong about the importance of JITs. At least until SquirrelFish has gone through a few rounds of optimizations.
- ECMAScript 4 type annotations can clearly help in performance critical code, but most of the web executes in untyped, vanilla JavaScript.
Notes on my tests: Running SunSpider, tamarin-tracing, tamarin-central, and SquirrelFish all pulled from source on 2008-06-02. I ran the test on a 2.4 Ghz iMac. Raw numbers from the comparison runs are available here.
Running your own version of the tests
To reproduce these tests, build WebKit, build tamarin-tracing and tamarin-central from Mozilla.org, and install the Flex SDK for a bytecode compiler. Then,
- Set up your environment as follows:
DYLD_FRAMEWORK_PATH="~/jsbench/WebKit/WebKitBuild/Release"
ASC="~/jsbench/asc.jar"
GLOBALABC="~/jsbench/tamarin-tracing/core/builtin_full.abc"
- Create a “timer.js” file that adds getTimer to the SunSpider benchmark:
function getTimer() { return new Date(); } - Create a “jscore” script that will run the original SunSpider AS source files instead of the ABC bytecode files:
#!/bin/sh
~/jsbench/WebKit/WebKitBuild/Release/testkjs -f ~/jsbench/timer.js -f `echo $1 | sed s/abc/as/` - And call the runtests.py script in the SunSpider test/performance sub-directory:
./runtests.py --avm ~/research/jsbench/jscore --avm2 ~/research/jsbench/tracing-avmshell
./runtests.py --avm ~/research/jsbench/jscore --avm2 ~/research/jsbench/central-avmshell
Technorati Tags: SquirrelFish, Tamarin, WebKit, Flash, ActionScript, JavaScript
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