[Bug-gnubg] calculate_half_inputs - potential speed up

[Ian Shaw]

Hi guys,

 

As I was pondering how gnubg evaluates positions, I realised that most of the time, the opponent’s board layout is the same whatever move the player makes.  There are only likely to be a couple of changes, when chequers are hit. If the opponent fails to enter from the bar, the position could even repeat across moves.

 

The results of calculate_half_inputs for the opposing side could therefore be re-used for many positions, which could lead to a saving in processing if they are cached. Is this done at present? Or would checking for a cache entry itself take up too much time?

 

Regards,

Ian Shaw