Corrects a functional change in a cleanup patch.

This corrects a functional change in
https://github.com/official-stockfish/Stockfish/commit/ddcbacd04d1c860e808202ce8c1206c8acdca627
changing evaluation of KPPvK. Bench remains unchanged at low depth

With this patch, 8/8/5k1p/8/7p/7K/8/8 b - - 1 11 is again correctly evaluated as a draw.

closes https://github.com/official-stockfish/Stockfish/pull/2807

Bench: 4366686

diff --git a/src/endgame.cpp b/src/endgame.cpp
index 40f49dce5018d08aaffd60468fd60e6a195a1021..a8ceb648776e42580e1d7ae788f1973c017ccc2b 100644 (file)
--- a/src/endgame.cpp
+++ b/src/endgame.cpp
@@ -589,8 +589,8 @@ ScaleFactor Endgame<KPsK>::operator()(const Position& pos) const {
   Bitboard strongPawns = pos.pieces(strongSide, PAWN);
 
   // If all pawns are ahead of the king on a single rook file, it's a draw.
-  if (!((strongPawns & ~FileABB) || (strongPawns & ~FileHBB)) &&
-      !(strongPawns & ~passed_pawn_span(weakSide, weakKing)))
+  if (   !(strongPawns & ~(FileABB | FileHBB))
+      && !(strongPawns & ~passed_pawn_span(weakSide, weakKing)))
       return SCALE_FACTOR_DRAW;
 
   return SCALE_FACTOR_NONE;