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From "Aleksey Shipilev" <aleksey.shipi...@gmail.com>
Subject Re: [perf] Comparative benchmarking
Date Tue, 06 Nov 2007 22:02:05 GMT
On 07 Nov 2007 00:27:25 +0300, Egor Pasko <egor.pasko@gmail.com> wrote:
> Vladimir, guess what? :) I actually mixed several things
> altogether.
<giggly>(sigh) As usual, miracle does not happen :) I dreamed to see
software sqrt() implementation that could be faster than hardware one.
</giggly>

> So, we are left with SSE asm that can be inlined by JIT and AFAI can
> see it is not as fast as HotSpot? Weird :)
No, for now we have just the intrinsic in native code, so we also have
overheads for JNI transition (and it is heavy!), parameter passing,
chains of calls, etc. I believe that sqrt() magic will lead that NBody
performance very close to RI.

BTW, in my thought this benchmark is like the top of the iceberg
called "FP performance problems".

Thanks,
Aleksey.

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