Oh, sorry, I completely forgot to do the 2d-4d tests in Magma. I'll try and do that in the next few days. Sooo busy at present.
Your timings are surprisingly low. Can you tell me which files perform the Z/pZ[x] GCD? I'd be very interested to see your code. You also mention that you made improvements. Is there anything that might be considered new, i.e. improvements I should consider incorporating in my own code. I sincerely doubt that FLINT can match those timings (though I haven't checked). The use of int* probably makes some difference. I use unsigned long *. I do have some pretty efficient division code, but I admit it could certainly be improved somewhat. Bill. On 22 Jan, 18:42, parisse <bernard.pari...@ujf-grenoble.fr> wrote: > > 1d: 0.00168s, 0.01692s and 0.0453s > > mod-1d: 0.00067s, 0.00981s, 0.0244s > > > Your timings (on a 2.2 Ghz Opteron!!) > > > 1-d:0.00018, 0.009, 0.034 > > mod 1-d: 7.5e-5, 0.0022, 0.007 > > > So you look to be well ahead of Magma! Did you do something special > > for small moduli, such as packing multiple coefficients into a limb? > > No. I'm using int * as data structure for polynomial in the modular > gcd algorithm, and it should work with modulo < 2^31 (there is a small > asm inline code for multiplication + addition followed by mod > reduction but it is mainly intended for 32 bits i386 processors to > avoid using long long which is somewhat stupid since the processor has > an imul and idiv instructions that can handle signed 32 bit > multiplication to 2 register over 64 bits). Since division inside the > gcd algorithm involves most of the time a polynomial of degree n by a > polynomial of degree n-1, I have also implemented a special case for > handling such divisions (this spares one mod reduction over 2 and > compute the remainder in one loop instead of 2). I also hope that my > time is accurate... > If you have the opportunity of running 2-d to 4-d fermat tests, I'd be > very interested to get the results (I don't know if inputs are > available for magma somewhere). > Thanks! --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
