simplified forward ranks.

[stockfish] / src / pawns.cpp

diff --git a/src/pawns.cpp b/src/pawns.cpp
index 55462bcf1ca16c2054fab08d1c80826bdc166780..761d770e6772534ac15b859e210d901b47430918 100644 (file)
--- a/src/pawns.cpp
+++ b/src/pawns.cpp
@@ -208,7 +208,7 @@ Value Entry::evaluate_shelter(const Position& pos, Square ksq) {
   constexpr Direction Down = (Us == WHITE ? SOUTH : NORTH);
   constexpr Bitboard  BlockRanks = (Us == WHITE ? Rank1BB | Rank2BB : Rank8BB | Rank7BB);
 
-  Bitboard b = pos.pieces(PAWN) & (forward_ranks_bb(Us, ksq) | rank_bb(ksq));
+  Bitboard b = pos.pieces(PAWN) & ~forward_ranks_bb(Them, ksq);
   Bitboard ourPawns = b & pos.pieces(Us);
   Bitboard theirPawns = b & pos.pieces(Them);