[ELDK] Fwd: OpenJDK and Other Questions

Wolfgang Denk wd at denx.de
Mon Sep 22 20:49:28 CEST 2008

Dear Jason,

in message <8f9e78f00809221051m77192e40u9655b3ecfec12c6c at mail.gmail.com> you wrote:
> I've been wondering about how large the performance penalty might
> be...and was already planning to pick up a 440-series board with a FPU
> soon in order to do some benchmarking.

I'm afraid  it's  impossible  to  tell  without  defining  your  very
specific  application mix. And even then it depends a lot on what you
are doing, and how. The same algoithm implmented in one  language  or
another  may make a huge dofference - for example, when Perl does all
internal data representation using floating point numbers.

> My initial hope was that we could avoid most floating-point operations
> in our developed code. Not sure however if there other places in the
> open source platforms I'm aiming to use - or the underlying VM where
> it would be impossible to avoid FP maths.

Normally it's not that critical for most real-world applications, but
as mentioned before - only your own application mix is relevant here.

> SSL/TLS and encryption operations will also likely be a problem. I
> don't know much about the Turbo Security Engine that ships with 440EPx
> but it seems like that might be a necessity provided it works properly
> with the operating system and VM.

Well, you need appropriate drivers to support the SE, and so far none
are available  yet  from  mainline  Linux.  AMCC  has  just  recently
(yesterday or today, I think) posted patches in that direction on the
crypto  mailing  list,  but  I  have  no information about quality or
features yet.

> If anyone is interested please let me know and I'll be happy to share
> some of my findings, progress updates, etc.

Please do. This information may be interesting to many of us here on
the list.

Best regards,

Wolfgang Denk

DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
"There are things that are so serious that you can  only  joke  about
them"                                                    - Heisenberg

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