I don't have the two Gray code tables, so it would be good to get your version. Also my code is currently a mess, so it would be good to clean it up by merging with a cleaner version (yours). Tomorrow I'll check carefully what I've changed and try and merge the ideas if there are any you don't have which definitely improve performance on the Opteron.
The speedups I am seeing from the ifs are possibly a feature of the Opteron cache algorithms. It is very sensitive when things just begin to fall out of cache, as they certainly are here. Not combining with the zero row just nudges things closer in to the cache boundary since it never has to read that row. I have checked and the speedups are quite reproducible, and they definitely come from the ifs, though I am now using a crossover with Strassen of 7200!! Bill. On 18 May, 00:12, Martin Albrecht <[EMAIL PROTECTED]> wrote: > > I suppose that this might be due to the ends of rows all being zero as > > they aren't a multiple of 64 bits long. But I checked for 16384x16384 > > and we are nearly down to the speed of Magma there too. I just don't > > get it. The coinflip has to be broken I think. > > If one uses M4RI with the new patch from within Sage another PRBG is used, but > coinflip should be fine. Don't see these speedups (but I have two Gray code > tables and this warrants for more if's) > > Hi, I think we might consider merging our two forks again? Or do you also have > the two Gray code tables? Are your timings on the Opteron? Because then > things look really goo since mine are on the C2D. > > Exciting times, > Martin > > -- > name: Martin Albrecht > _pgp:http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x8EF0DC99 > _www:http://www.informatik.uni-bremen.de/~malb > _jab: [EMAIL PROTECTED] --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
