X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fhistory.cpp;h=a57e6de8da5a5324d09f586304130b64881573f1;hp=22116412c863c4e0a5efadbed4abf61931eb7e2b;hb=41816b7ced99c0bd096607fd8a35dbc0b427d455;hpb=942c18ef6620967921049ba24f25e08d710c947e

diff --git a/src/history.cpp b/src/history.cpp
index 22116412..a57e6de8 100644
--- a/src/history.cpp
+++ b/src/history.cpp
@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2009 Marco Costalba
+  Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -42,6 +42,7 @@ History::History() { clear(); }
 
 void History::clear() {
   memset(history, 0, 2 * 8 * 64 * sizeof(int));
+  memset(maxStaticValueDelta, 0, 2 * 8 * 64 * sizeof(int));
 }
 
 
@@ -94,3 +95,21 @@ int History::move_ordering_score(Piece p, Square to) const {
 
   return history[p][to];
 }
+
+
+/// History::set_gain() and History::gain() store and retrieve the
+/// gain of a move given the delta of the static position evaluations
+/// before and after the move.
+
+void History::set_gain(Piece p, Square to, Value delta)
+{
+  if (delta >= maxStaticValueDelta[p][to])
+      maxStaticValueDelta[p][to] = delta;
+  else
+      maxStaticValueDelta[p][to]--;
+}
+
+Value History::gain(Piece p, Square to) const
+{
+  return Value(maxStaticValueDelta[p][to]);
+}