Hi Dominic, Dominic Steinitz wrote:
I've been playing around some more trying improve the performance of the SHA1 implmentation in the crypto library. I've isolated one of the functions and implemented it using
a) unfold
and
b) STUArray
The STUArray implementation is about twice as fast but I was expecting an order of magnitude improvement given I thought I would have been allocating 16 x 80 new 32 bit words with unfold but nothing with the STUArray.
Should I have been disappointed?
dom@heisenberg:~/sha12> time ./arrTest 17 STUArray > /dev/null
real 0m11.102s user 0m9.129s sys 0m0.112s dom@heisenberg:~/sha12> time ./arrTest 17 Unfold > /dev/null
real 0m18.381s user 0m16.361s sys 0m0.212s
<code snipped>
I did not have time to look into your code yet. But the question whether this is only a constant factor improvement or an implementation with a different time complexity can only be researched by a series of experiments with different input sizes. An interpretation of a series of results of experiments is more meaningful than just one data point. Greets, Jean-Marie