X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fevaluate.cpp;h=c5af2f89524e5f9c04b89bb5c1780d8caa105911;hp=68984802e5193185aae5b3f648173563948bd94d;hb=12c0dfc11364f915d90032a3dfbac3ed8f39db0a;hpb=2d82db1d14631de38d158f16e31f374147bcfd6a

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 68984802..c5af2f89 100644
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -821,7 +821,8 @@ Value do_evaluate(const Position& pos, Value& margin) {
                 // If there is an enemy rook or queen attacking the pawn from behind,
                 // add all X-ray attacks by the rook or queen. Otherwise consider only
                 // the squares in the pawn's path attacked or occupied by the enemy.
-                if (forward_bb(Them, s) & pos.pieces(Them, ROOK, QUEEN) & pos.attacks_from<ROOK>(s))
+                if (   (forward_bb(Them, s) & pos.pieces(Them, ROOK, QUEEN)) // Unlikely
+                    && (forward_bb(Them, s) & pos.pieces(Them, ROOK, QUEEN) & pos.attacks_from<ROOK>(s)))
                     unsafeSquares = squaresToQueen;
                 else
                     unsafeSquares = squaresToQueen & (ei.attackedBy[Them][ALL_PIECES] | pos.pieces(Them));