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Octane now includes asm.js benchmarks, and V8 doesn't attempt to support "use asm". This gives SpiderMonkey an advantage in the benchmark. I think it's quite i

by Sephr 12y ago

Octane now includes asm.js benchmarks, and V8 doesn't attempt to support "use asm". This gives SpiderMonkey an advantage in the benchmark. I think it's quite impressive how close V8 is in performance to SpiderMonkey which actually goes out of it's way to support "use asm".

xooyoozoo 12y ago
Octane is Google's own benchmark suite. I don't think getting beaten on your own hand-picked set of performance metrics satisfies any definition of "impressive".
- afsina 12y ago
  It sure is far better than idiotic SunSpider. They are close to real-life application examples. If they really wanted to hand-pick they would not include asm.js benchmarks, where Firefox has a certain advantage.
  - nnethercote 12y ago
    Octane is half good and half rubbish: https://blog.mozilla.org/nnethercote/2012/08/24/octane-minus-v8/ https://blog.mozilla.org/nnethercote/2012/08/24/octane-minus... The notable thing about this achievement is that for a very long time V8 was miles ahead of the competition on its own benchmark (first V8bench, and now Octane), as the graphs at http://arewefastyet.com/ http://arewefastyet.com/ show.
nnethercote 12y ago
This comes down to your definition of "support". Unlike SpiderMonkey, V8 doesn't have a special mode for "use asm" code, as far as I know. E.g. it still does JIT compilation, unlike SpiderMonkey, which does AOT compilation. But the V8 team is certainly working on making asm.js code fast. This is clear from the fact that V8's performance on asm.js benchmarks has increased significantly since asm.js was first announced. (As you note, they put an asm.js test in their own benchmark suite.) And even if V8 doesn't have a special mode for asm.js, they're benefitting from asm.js's existence, because asm.js makes clear exactly which subset of JavaScript they need to be optimizing for.
- cpeterso 12y ago
  V8 has an experimental new JIT called "TurboFan". AFAIK, it doesn't do AOT compilation of asm.js code, but the "use asm" directive (among other cases) will force TurboFan mode. https://news.ycombinator.com/item?id=8117091 https://news.ycombinator.com/item?id=8117091

by Sephr 12y ago

xooyoozoo 12y ago

Octane is Google's own benchmark suite. I don't think getting beaten on your own hand-picked set of performance metrics satisfies any definition of "impressive".

afsina 12y ago
It sure is far better than idiotic SunSpider. They are close to real-life application examples. If they really wanted to hand-pick they would not include asm.js benchmarks, where Firefox has a certain advantage.
- nnethercote 12y ago
  Octane is half good and half rubbish: https://blog.mozilla.org/nnethercote/2012/08/24/octane-minus-v8/ https://blog.mozilla.org/nnethercote/2012/08/24/octane-minus... The notable thing about this achievement is that for a very long time V8 was miles ahead of the competition on its own benchmark (first V8bench, and now Octane), as the graphs at http://arewefastyet.com/ http://arewefastyet.com/ show.

nnethercote 12y ago

This comes down to your definition of "support". Unlike SpiderMonkey, V8 doesn't have a special mode for "use asm" code, as far as I know. E.g. it still does JIT compilation, unlike SpiderMonkey, which does AOT compilation. But the V8 team is certainly working on making asm.js code fast. This is clear from the fact that V8's performance on asm.js benchmarks has increased significantly since asm.js was first announced. (As you note, they put an asm.js test in their own benchmark suite.) And even if V8 doesn't have a special mode for asm.js, they're benefitting from asm.js's existence, because asm.js makes clear exactly which subset of JavaScript they need to be optimizing for.

cpeterso 12y ago
V8 has an experimental new JIT called "TurboFan". AFAIK, it doesn't do AOT compilation of asm.js code, but the "use asm" directive (among other cases) will force TurboFan mode. https://news.ycombinator.com/item?id=8117091 https://news.ycombinator.com/item?id=8117091