Simplify semiopen_file (#2165)

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 5750d82a7281bbd9ff91f6b22f137b9e9fac0600..86f73563ef262a9e2914597320b0adfef8818e59 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -357,8 +357,8 @@ namespace {
                 score += RookOnPawn * popcount(pos.pieces(Them, PAWN) & PseudoAttacks[ROOK][s]);
 
             // Bonus for rook on an open or semi-open file
-            if (pos.is_semiopen_file(Us, file_of(s)))
-                score += RookOnFile[bool(pos.is_semiopen_file(Them, file_of(s)))];
+            if (pos.is_on_semiopen_file(Us, s))
+                score += RookOnFile[bool(pos.is_on_semiopen_file(Them, s))];
 
             // Penalty when trapped by the king, even more if the king cannot castle
             else if (mob <= 3)
@@ -649,7 +649,7 @@ namespace {
                 // in the pawn's path attacked or occupied by the enemy.
                 defendedSquares = unsafeSquares = squaresToQueen = forward_file_bb(Us, s);
 
-                bb = forward_file_bb(Them, s) & pos.pieces(ROOK, QUEEN) & pos.attacks_from<ROOK>(s);
+                bb = forward_file_bb(Them, s) & pos.pieces(ROOK, QUEEN);
 
                 if (!(pos.pieces(Us) & bb))
                     defendedSquares &= attackedBy[Us][ALL_PIECES];
@@ -719,9 +719,7 @@ namespace {
     behind |= shift<Down+Down>(behind);
 
     int bonus = popcount(safe) + popcount(behind & safe);
-    int weight =  pos.count<ALL_PIECES>(Us)
-               - (16 - pos.count<PAWN>()) / 4;
-
+    int weight = pos.count<ALL_PIECES>(Us) - 1;
     Score score = make_score(bonus * weight * weight / 16, 0);
 
     if (T)