50-moves rule improvement for transposition table

[stockfish] / src / endgame.cpp

diff --git a/src/endgame.cpp b/src/endgame.cpp
index 7c4efa3cb425dfe4717c12e7ff1b26c039f730f6..276b942eac55642a3ac3212b6152f797462816bc 100644 (file)
--- a/src/endgame.cpp
+++ b/src/endgame.cpp
@@ -2,7 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
-  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+  Copyright (C) 2015-2020 Marco Costalba, Joona Kiiski, Gary Linscott, 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
@@ -74,7 +74,7 @@ namespace {
     assert(pos.count<PAWN>(strongSide) == 1);
 
     if (file_of(pos.square<PAWN>(strongSide)) >= FILE_E)
-        sq = Square(sq ^ 7); // Mirror SQ_H1 -> SQ_A1
+        sq = Square(int(sq) ^ 7); // Mirror SQ_H1 -> SQ_A1
 
     return strongSide == WHITE ? sq : ~sq;
   }
@@ -88,27 +88,28 @@ namespace Endgames {
 
   void init() {
 
-      add<KPK>("KPK");
-      add<KNNK>("KNNK");
-      add<KBNK>("KBNK");
-      add<KRKP>("KRKP");
-      add<KRKB>("KRKB");
-      add<KRKN>("KRKN");
-      add<KQKP>("KQKP");
-      add<KQKR>("KQKR");
-      add<KNNKP>("KNNKP");
-
-      add<KNPK>("KNPK");
-      add<KNPKB>("KNPKB");
-      add<KRPKR>("KRPKR");
-      add<KRPKB>("KRPKB");
-      add<KBPKB>("KBPKB");
-      add<KBPKN>("KBPKN");
-      add<KBPPKB>("KBPPKB");
-      add<KRPPKRP>("KRPPKRP");
+    add<KPK>("KPK");
+    add<KNNK>("KNNK");
+    add<KBNK>("KBNK");
+    add<KRKP>("KRKP");
+    add<KRKB>("KRKB");
+    add<KRKN>("KRKN");
+    add<KQKP>("KQKP");
+    add<KQKR>("KQKR");
+    add<KNNKP>("KNNKP");
+
+    add<KNPK>("KNPK");
+    add<KNPKB>("KNPKB");
+    add<KRPKR>("KRPKR");
+    add<KRPKB>("KRPKB");
+    add<KBPKB>("KBPKB");
+    add<KBPKN>("KBPKN");
+    add<KBPPKB>("KBPPKB");
+    add<KRPPKRP>("KRPPKRP");
   }
 }
 
+
 /// Mate with KX vs K. This function is used to evaluate positions with
 /// king and plenty of material vs a lone king. It simply gives the
 /// attacking side a bonus for driving the defending king towards the edge
@@ -364,7 +365,7 @@ ScaleFactor Endgame<KBPsK>::operator()(const Position& pos) const {
       && pos.count<PAWN>(weakSide) >= 1)
   {
       // Get weakSide pawn that is closest to the home rank
-      Square weakPawnSq = backmost_sq(weakSide, pos.pieces(weakSide, PAWN));
+      Square weakPawnSq = frontmost_sq(strongSide, pos.pieces(weakSide, PAWN));
 
       Square strongKingSq = pos.square<KING>(strongSide);
       Square weakKingSq = pos.square<KING>(weakSide);