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 -~----------~----~----~----~------~----~------~--~---
