Jean-Pierre Flori on Thu, 14 Jan 2016 17:05:36 +0100 |
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Re: Faster exponentiation in some extensions of finite fields of small characteristics |
Looking at what Peter did, I now see I should just wrap his code! http://pari.math.u-bordeaux.fr/archives/pari-dev-1510/msg00004.html 2016-01-14 13:32 GMT+01:00 Jean-Pierre Flori <jpflori@gmail.com>: > Should be better now. > > 2016-01-14 13:22 GMT+01:00 Jean-Pierre Flori <jpflori@gmail.com>: >> It seems it was an old buggy version of the patch. >> I'm trying to relocate the right commit. >> >> 2016-01-14 11:58 GMT+01:00 Jean-Pierre Flori <jpflori@gmail.com>: >>> Dear all, >>> >>> Here is a preliminary patch to speed up exponentiation in some >>> extensions of finite fields of small characteristics (< size of >>> machine word/2). >>> >>> It packs more coefficients of the polynomial representation over the >>> prime field into machine words when the finite field element is mapped >>> to a multiprecision integer (i.e. KS). >>> Two functions are added: >>> * one function which packs 4 coeffs into a machine word, >>> * one generic funciton which packs the coeffs as much as possible >>> possibly crossing machine words boundaries. >>> >>> I did not take care of adding new tuning parameters or smartly >>> choosing between the different functions, e.g. calling the >>> 4-coeffs-in-1-word function when the (product) coeff size is >>> BITS_IN_LONG/4-\epsilon might be more efficient than using the generic >>> function which does more complicated packing when the polynomial >>> degree is not large. >>> >>> I did not add (yet) optimal packing when the product coeffs are larger >>> than a machine word. >>> >>> I did not really check it is bug free. >>> >>> Best, >>> -- >>> Jean-Pierre Flori >> >> >> >> -- >> Jean-Pierre Flori > > > > -- > Jean-Pierre Flori -- Jean-Pierre Flori