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! Brian
