On Sunday 05 September 2010 16:41:14 Jeroen Demeyer wrote: > On 2010-09-04 00:05, Bill Hart wrote: > > Regarding the internal undocumented functions used by Pari, if there > > are no missing symbol errors when you build against MPIR, then it is > > likely these are mpn functions that were formerly undocumented, but > > now part of the documented interface. I think it would be safe to > > leave that flag set (so long as it actually compiles and links). > > PARI doesn't use any undocumented functions, it uses the structure of > the mpz_t type (see MPIR documentation, section 16.1). > > It would be useful for PARI (and hence Sage) to have a public interface > for mpn_divexact (currently, there is only mpn_divexact_by3 and > mpn_divexact_by3c). > > Jeroen.
Hi There are a few problems with this , GMP would have to have the same interface or I certain Pari would not use it. There is a second more subtle problem , do you want divexact (ie division which is only correct when exact ) or divrem_hensel (ie division which gives the hensel(2-adic) quotient ) If you use mpn_divexact and are relying on it to be hensel division then when we change the algorithm later for a faster one (ie bidirectional) then your code will break , or we will have to fudge it. For example the old mpn_divexact_by3c was hensel division , but the new one (which is about twice as fast) is not , and we had to fudge the feed-in and wind-out code to get the same remainders. Jason -- You received this message because you are subscribed to the Google Groups "mpir-devel" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/mpir-devel?hl=en.
