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Workload type primality proving
PRP tests
First release < 2003
Latest version 3.8.21

LLR (Lucas Lehmer Riesel) is probably the fastest program available to perform primality test on numbers of the form k*2n ± c.

It is written by Jean Penné and uses the most recent release (28.14) of George Woltman's Gwnums library, to do fast multiplications and squarings of large integers modulo N.

LLR can take input file from Paul Jobling's NewPGen and also from some ABC format files.

LLR's port for CUDA-based GPUs is called llrCUDA.


Main algorithms:

Apart from these, the program also implements "special algorithms" for Gaussian-Mersenne norms and Wagstaff numbers (2p+1)/3. The latter uses a strong Fermat PRP-test and the Vrba-Reix algorithm.


Example input file input.abc:

ABC $a

Then running the program with following command:

./llr64 -d input.abc

will test 2521-1 (M13) for primality with APR-CL test.

External links