$ make mpi NAME=prime-gmpmpi mpicc -g -o prime-gmpmpi prime-gmpmpi.c /usr/local/lib/libgmp.a /usr/local/lib/libsprng.a cc: /usr/local/lib/libgmp.a: linker input file unused because linking not done cc: /usr/local/lib/libsprng.a: linker input file unused because linking not done $ mpirun -np 8 prime-gmpmpi Do you want to test a number? 0= done 1=yes 1 Please input the number you wish to check 2305843009213693951 I heard 1 from 0. I heard 1 from 1. I heard 1 from 2. I heard 1 from 3. I heard 1 from 4. I heard 1 from 5. I heard 1 from 6. I heard 1 from 7. This is a prime. wall clock time = 19.005737 Do you want to test a number? 0= done 1=yes 1 Please input the number you wish to check 2305843009213693953 I heard 0 from 0. I heard 1 from 1. I heard 1 from 2. I heard 1 from 3. I heard 1 from 4. I heard 1 from 5. I heard 1 from 6. I heard 1 from 7. This is not a prime. wall clock time = 17.773776 Do you want to test a number? 0= done 1=yes 0