Tweak Late Move Reduction at root

[stockfish] / src / position.cpp

diff --git a/src/position.cpp b/src/position.cpp
index 4358f9685ed904ef5ce82c04974caa0422969774..db66f416559c7add343f9e035bff4b1842566868 100644 (file)
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -330,16 +330,15 @@ Position& Position::set(const string& fenStr, bool isChess960, StateInfo* si, Th
 void Position::set_castling_right(Color c, Square rfrom) {
 
   Square kfrom = square<KING>(c);
-  CastlingSide cs = kfrom < rfrom ? KING_SIDE : QUEEN_SIDE;
-  CastlingRight cr = (c | cs);
+  CastlingRights cr = c & (kfrom < rfrom ? KING_SIDE: QUEEN_SIDE);
 
   st->castlingRights |= cr;
   castlingRightsMask[kfrom] |= cr;
   castlingRightsMask[rfrom] |= cr;
   castlingRookSquare[cr] = rfrom;
 
-  Square kto = relative_square(c, cs == KING_SIDE ? SQ_G1 : SQ_C1);
-  Square rto = relative_square(c, cs == KING_SIDE ? SQ_F1 : SQ_D1);
+  Square kto = relative_square(c, cr & KING_SIDE ? SQ_G1 : SQ_C1);
+  Square rto = relative_square(c, cr & KING_SIDE ? SQ_F1 : SQ_D1);
 
   castlingPath[cr] =   (between_bb(rfrom, rto) | between_bb(kfrom, kto) | rto | kto)
                     & ~(square_bb(kfrom) | rfrom);
@@ -1300,14 +1299,14 @@ bool Position::pos_is_ok() const {
   }
 
   for (Color c : { WHITE, BLACK })
-      for (CastlingSide s : {KING_SIDE, QUEEN_SIDE})
+      for (CastlingRights cr : {c & KING_SIDE, c & QUEEN_SIDE})
       {
-          if (!can_castle(c | s))
+          if (!can_castle(cr))
               continue;
 
-          if (   piece_on(castlingRookSquare[c | s]) != make_piece(c, ROOK)
-              || castlingRightsMask[castlingRookSquare[c | s]] != (c | s)
-              || (castlingRightsMask[square<KING>(c)] & (c | s)) != (c | s))
+          if (   piece_on(castlingRookSquare[cr]) != make_piece(c, ROOK)
+              || castlingRightsMask[castlingRookSquare[cr]] != (cr)
+              || (castlingRightsMask[square<KING>(c)] & (cr)) != (cr))
               assert(0 && "pos_is_ok: Castling");
       }