View Single Post
Old 2011-02-28, 21:52   #7
rogue's Avatar
Apr 2003
Between here and the

2·32·17·19 Posts

Originally Posted by Jean Penné View Post

These two bugs are now fixed :

- For 10^500+961, it is really a bug of the strong Fermat PRP code in the Llr.c file. It will be fixed in the Development version ; here is the correct behaviour :

Starting probable prime test of 10^500+961
Using all-complex FFT length 192, a = 3
10^500+961 is base 3-Strong Fermat PRP! Time : 121.052 ms.
Starting Lucas sequence
Using all-complex FFT length 192, P = 5, Q = 3
10^500+961 is strong-Fermat and Lucas PRP, Starting Frobenius test sequence
Using all-complex FFT length 192, Q = 3
10^500+961 is strong-Fermat, Lucas and Frobenius PRP! (P = 5, Q = 3, D = 13) Time : 72.780 ms.

For 5*10^19737+3, it is a gwnum problem : gwnum chooses a full-complex 4K FFT, which seems to be too small, and causes a segmentation fault after a few iterations...
I suspect that it might be CPU specific or specific to the 32-bit version. On 64-bit MacIntel, pfgw chooses the 4K FFT and it runs without a problem. Granted pfgw and llr use different code. I would have to try with 64-bit llr on MacIntel to know for certain.
rogue is offline   Reply With Quote