Update on 8014320

Brian Burkhalter brian.burkhalter at oracle.com
Mon Dec 23 19:53:56 UTC 2013

Hello Tim,

On Dec 23, 2013, at 11:37 AM, Tim Buktu wrote:

> I've been quiet because real life needed my attention.

Strange how that works. ;-0

> Obviously, the Schoenhage-Strassen and Barrett algorithms are not going
> to make it into JDK8. I hope that is not a problem for anyone.

Correct. Sorry about that. There simply was not enough time.

> We
> shouldn't use the word "problem" anyway but rather think of it as an
> opportunity :-) for more refinement and testing.
> Improvements I have planned are:
> * Compact storage of DFT vectors. At the moment, they are stored as
> numbers modulo 2^2^(n+1) when (2^2^n)+1 would suffice. This will save
> memory and may speed up the DFT and IDFT steps.
> * Use Bailey's algorithm recursively if it improves cache locality and
> doesn't add too much complexity to the code.
> * Maybe add a multiplyParallel() method, now that dft() and idft() use
> Bailey's algorithm which should make them easy to parallelize.
> * See if dft() and idft() can be made faster on 64-bit CPUs by using
> long[][] arrays instead of int[][].

As I've not yet studied the implementation as it stands I cannot really comment with authority, but that all sounds reasonable.

> As always, comments are welcome.
> Merry Chris... I mean, Holidays and a happy new year to everyone!

Thanks and likewise!


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