On Monday 11 October 2010 07:05:20 you wrote:

Hi,

These results seem different from the samples.

Thanks. The numbers are quite impressive. Although the quotients (hence speedups) are generally much larger, the ranking doesn't differ much. For round :: x -> Int, via C is a big win. For round :: x -> Integer and properFraction :: Double -> (Integer, Double), going via C doesn't seem to make much difference on 64 bits, but they do on 32. That's probably because a Double mantissa is a smallInteger on 64 bits. Overall, your timings support going via C for round and properFraction :: Double -> (Integer, Double). In two cases, it makes not much difference on 64 bits but is a big gain on 32, for round :: x -> Int, it's a big win on both.

I was surprised that the "via Integer" results appear faster than the Int results.

No, the numbers are (Prelude time / new time), so the larger the number, the better. Sorry for not making that clear in the README.

Vivian

Cheers, Daniel