i'm implementing a benchmark which includes a detailed specification for a random number generator. for any of the kernels outlined in the benchmark, i might have to generate a set of random numbers R, which has a length n, using the following formulas: R[k] = ((2^-46)(X[k])) mod 2^46, where X[k] = (a^k)s where the values of a and s are constant and defined below. many of the kernels in the benchmark require a large number of randoms to be generated (in the tens of millions). when i invoke the following getRandAt function that many times to build up a list, evaluation of the list takes forever (somewhere between 5 and 10 minutes). i've tried optimizing this several different ways, with no luck. i though i might post my code here and see if anyone notices anything i'm doing wrong that might be causing such a large bottleneck: --constants a :: Int64 a = 5^13 divisor :: Int64 divisor = 2^46 multiplier :: Float multiplier = 2**(-46) --gets r[k], which is the value at the kth --position in the overall sequence of --pseudorandom numbers getRandAt :: Int64 -> Int64 -> Float getRandAt 0 seed = multiplier * (fromIntegral seed) getRandAt k seed = multiplier * (fromIntegral x_next) where x_prev = (a^k * seed) `mod` divisor x_next = (a * x_prev) `mod` divisor thanks all in advance for your help! -james