X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fhistory.cpp;h=8c20f7e0578feb521aa54b10bf25da7e2089f7ff;hp=22116412c863c4e0a5efadbed4abf61931eb7e2b;hb=a0005ba45f7d5c97a096b79065c0b83ae3d81afa;hpb=942c18ef6620967921049ba24f25e08d710c947e

diff --git a/src/history.cpp b/src/history.cpp
index 22116412..8c20f7e0 100644
--- a/src/history.cpp
+++ b/src/history.cpp
@@ -42,6 +42,7 @@ History::History() { clear(); }
 
 void History::clear() {
   memset(history, 0, 2 * 8 * 64 * sizeof(int));
+  memset(maxStaticValueDelta, 0, 16 * 64 * 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 from, Square to, Value delta)
+{
+  if (delta >= maxStaticValueDelta[p][from][to])
+      maxStaticValueDelta[p][from][to] = delta;
+  else
+      maxStaticValueDelta[p][from][to]--;
+}
+
+Value History::gain(Piece p, Square from, Square to) const
+{
+  return Value(maxStaticValueDelta[p][from][to]);
+}