; is F a factor of 2^N-1
macro MFactorQ N*,F*
        local B,T,D
        D = 1 + bsr F
        B = 1
        T = 1
        while B < N & T
                if (B+D) <= N
                        T = ((T+1) shl D)-1
                        B = B + D
                        T = T mod F
                else
                        T = T + T + 1
                        B = B + 1
                        if T >= F
                                T = T mod F
                        end if
                end if
        end while
        repeat 1,t:T,b:B,f:F
                if T = 0
                        display `f,' divides 2^',`b,'-1.',13,10
                else
                        display '2^',`b,'-1 mod ',`f,' = ',`t,13,10
                end if
        end repeat
end macro

MFactorQ 1001664179, 1878753956886303627167 ; 2 min
MFactorQ 3930621659, 6134708376727152865752497 ; 10 min    

test-file.fasmg [66]:
        err 'No Output File'
Custom error: No Output File.
The terminal process terminated with exit code: 1    

Next I try to verify some data: There is list of cube sums at https://arxiv.org/abs/1604.07746v1