By the way, I still get the following warnings when building MPIR on AMD64:
gcd.c: In function 'mpz_rgcd': gcd.c:167: warning: implicit declaration of function 'mpn_rgcd' gcd.c: In function 'mpz_bgcd': gcd.c:171: warning: implicit declaration of function 'mpn_bgcd' gcd.c: In function 'mpz_sgcd': gcd.c:175: warning: implicit declaration of function 'mpn_sgcd' gcd.c: In function 'mpz_ngcd': gcd.c:179: warning: implicit declaration of function 'mpn_ngcd' Bill. On Dec 20, 11:37 pm, Bill Hart <goodwillh...@googlemail.com> wrote: > Hi Jason, > > I ran this on my Opteron which also has Magma. > > For two 2,000,000 bit numbers with a 1,000,000 bit GCD Magma takes > 0.42s per GCD but MPIR with Moller patches takes 3.7s (10098810860 > cycles) per GCD. > > Half GCD is not faster than fast euclidean until the sizes get quite > large. You have to do the timings for *much* larger integers. The time > that the new code takes should be negligible compared to the old code > for very large sizes due to the asymptotic speedup. At the moment > without the patches MPIR takes only 4.8s. It's clearly not working. > For example compare the timings on the GMP website: > > http://gmplib.org/devel/ > > Note that at around 1,000,000 bits it is 10 times faster, not 20% > faster. > > By the way, the code you posted has a variable missing in the final > printf. It always returns 0.00. > > Bill. > > On Dec 20, 8:59 pm, "Jason Martin" <jason.worth.mar...@gmail.com> > wrote: > > > I've been running speed some tests with the Moller patches, and it > > looks to me like they work just fine for larger numbers, but at > > smaller limb counts they are slower than the original code. I've > > attached my test code so that you can see what I'm doing. > > > I suspect that I need to add some tuning to figure out what the > > threshold values are for flipping to the half-gcd based scheme, but > > otherwise the patches seem to be sound. > > > for the random numbers in the test code here's what I see: > > > MPIR svn version 1487 (pre-patch): 17,900 cycles > > MPIR svn version 1503 (current): 16,000 cycles > > > --jason > > > Jason Worth Martin > > Asst. Professor of Mathematicshttp://www.math.jmu.edu/~martin > > > Makefile > > < 1KViewDownload > > > speed_test.c > > 3KViewDownload > > > read_time_stamp_counter.yasm > > 1KViewDownload --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "mpir-devel" group. To post to this group, send email to mpir-devel@googlegroups.com To unsubscribe from this group, send email to mpir-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/mpir-devel?hl=en -~----------~----~----~----~------~----~------~--~---
