Clean Up Castling in gives_check

[stockfish] / src / position.cpp

diff --git a/src/position.cpp b/src/position.cpp
index 12b1bd9a8c5332996794e1ea9549fa2b23ba10b3..954e5ffdf757637abed4591216004709b4c38c09 100644 (file)
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -564,8 +564,10 @@ bool Position::pseudo_legal(const Move m) const {
   Piece pc = moved_piece(m);
 
   // Use a slower but simpler function for uncommon cases
+  // yet we skip the legality check of MoveList<LEGAL>().
   if (type_of(m) != NORMAL)
-      return MoveList<LEGAL>(*this).contains(m);
+      return checkers() ? MoveList<    EVASIONS>(*this).contains(m)
+                        : MoveList<NON_EVASIONS>(*this).contains(m);
 
   // Is not a promotion, so promotion piece must be empty
   if (promotion_type(m) - KNIGHT != NO_PIECE_TYPE)
@@ -663,19 +665,15 @@ bool Position::gives_check(Move m) const {
       return  (attacks_bb<  ROOK>(square<KING>(~sideToMove), b) & pieces(sideToMove, QUEEN, ROOK))
             | (attacks_bb<BISHOP>(square<KING>(~sideToMove), b) & pieces(sideToMove, QUEEN, BISHOP));
   }
-  case CASTLING:
+  default: //CASTLING
   {
-      Square kfrom = from;
-      Square rfrom = to; // Castling is encoded as 'king captures the rook'
-      Square kto = relative_square(sideToMove, rfrom > kfrom ? SQ_G1 : SQ_C1);
-      Square rto = relative_square(sideToMove, rfrom > kfrom ? SQ_F1 : SQ_D1);
+      // Castling is encoded as 'king captures the rook'
+      Square ksq = square<KING>(~sideToMove);
+      Square rto = relative_square(sideToMove, to > from ? SQ_F1 : SQ_D1);
 
-      return   (attacks_bb<ROOK>(rto) & square<KING>(~sideToMove))
-            && (attacks_bb<ROOK>(rto, (pieces() ^ kfrom ^ rfrom) | rto | kto) & square<KING>(~sideToMove));
+      return   (attacks_bb<ROOK>(rto) & ksq)
+            && (attacks_bb<ROOK>(rto, pieces() ^ from ^ to) & ksq);
   }
-  default:
-      assert(false);
-      return false;
   }
 }
 
@@ -1017,7 +1015,7 @@ void Position::do_null_move(StateInfo& newSt) {
   }
 
   st->key ^= Zobrist::side;
-  prefetch(TT.first_entry(st->key));
+  prefetch(TT.first_entry(key()));
 
   ++st->rule50;
   st->pliesFromNull = 0;
@@ -1067,7 +1065,7 @@ bool Position::see_ge(Move m, Value threshold) const {
 
   assert(is_ok(m));
 
-  // Only deal with normal moves, assume others pass a simple see
+  // Only deal with normal moves, assume others pass a simple SEE
   if (type_of(m) != NORMAL)
       return VALUE_ZERO >= threshold;