Re: [gnugo-devel] paul_3_13.5.gz

[Inge Wallin]

> i wrote:
> > the patch cuts off around 600k (!) from the executable and must give a
> > measureable speedup as well (haven't checked).
> 
> today i checked the speed and got an unexpected result: the 1D
> version is a tiny little bit slower than the 2D one - the
> difference is 1 - 2 seconds on nngs.tst (which runs for a bit
> more than 20 minutes on my computer). i did the check three
> times and the results are very consistent.
> 
> either something went wrong or the rather large transformation[][]
> array (almost 43k) is not doing very fast. i'm going to look
> through the whole patch in search for a mistake. i'll post the
> results soon.

I haven't looked at the patch, but maybe this is a case of the slow
memory - fast CPU discrepancy.  A modern PC can execute quite a few
instructions while just waiting for one memory access.  It is somewhat
counter intuitive, but it is often faster to recompute a value than to
look it up in a memory table.

     -Inge