2 ply conthist

Bench: 9923161
SzilBalazs · Sep 3, 2023 · ff38160 · ff38160
1 parent 31b720e
commit ff38160
Showing 1 changed file with 27 additions and 3 deletions.
diff --git a/src/search/history.h b/src/search/history.h
@@ -50,7 +50,11 @@ namespace search {
 
             if ((ss - 1)->move.is_ok()) {
                 update_counter_moves(move, (ss - 1)->move);
-                update_history(conthist[(ss - 1)->pt][(ss - 1)->move.get_to()][move.get_from()][move.get_to()], depth * 100);
+                update_history(get_conthist_ref<1>(move, ss), depth * 100);
+            }
+
+            if ((ss - 2)->move.is_ok()) {
+                update_history(get_conthist_ref<2>(move, ss), depth * 100);
             }
         }
 
@@ -64,15 +68,25 @@ namespace search {
             update_history(butterfly[move.get_from()][move.get_to()], -depth * 100);
 
             if ((ss - 1)->move.is_ok()) {
-                update_history(conthist[(ss - 1)->pt][(ss - 1)->move.get_to()][move.get_from()][move.get_to()], -depth * 100);
+                update_history(get_conthist_ref<1>(move, ss), -depth * 100);
+            }
+
+            if ((ss - 2)->move.is_ok()) {
+                update_history(get_conthist_ref<2>(move, ss), -depth * 100);
             }
         }
 
         Score get_history(chess::Move move, SearchStack *ss) const {
             Score value = butterfly[move.get_from()][move.get_to()];
+
             if ((ss - 1)->move.is_ok()) {
-                value += 2 * conthist[(ss - 1)->pt][(ss - 1)->move.get_to()][move.get_from()][move.get_to()];
+                value += 2 * get_conthist<1>(move, ss);
+            }
+
+            if ((ss - 2)->move.is_ok()) {
+                value += get_conthist<2>(move, ss);
             }
+
             return value;
         }
 
@@ -107,6 +121,16 @@ namespace search {
             counter_moves[last_move.get_from()][last_move.get_to()] = move;
         }
 
+        template<Ply ply>
+        Score get_conthist(const chess::Move &move, SearchStack *ss) const {
+            return conthist[(ss - ply)->pt][(ss - ply)->move.get_to()][move.get_from()][move.get_to()];
+        }
+
+        template<Ply ply>
+        Score &get_conthist_ref(const chess::Move &move, SearchStack *ss) {
+            return conthist[(ss - ply)->pt][(ss - ply)->move.get_to()][move.get_from()][move.get_to()];
+        }
+
         static void update_history(Score &entry, Score bonus) {
             int scaled = bonus - entry * std::abs(bonus) / 32768;
             entry += scaled;