X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=5dc94a634d665b08e878931ac1b7bb38389da8fa;hp=0c81763155d078275263430b17b4a044269daeab;hb=55948623e7b8ad1fc6624cd06733b16d295eecb8;hpb=0504a6975d8f32ee9638e05b53ed32e3f7a7f4e1

diff --git a/src/position.cpp b/src/position.cpp
index 0c817631..5dc94a63 100644
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -68,22 +68,19 @@ PieceType min_attacker(const Bitboard* bb, const Square& to, const Bitboard& stm
                        Bitboard& occupied, Bitboard& attackers) {
 
   Bitboard b = stmAttackers & bb[Pt];
+  if (!b)
+      return min_attacker<Pt+1>(bb, to, stmAttackers, occupied, attackers);
 
-  if (b)
-  {
-      occupied ^= b & ~(b - 1);
-
-      if (Pt == PAWN || Pt == BISHOP || Pt == QUEEN)
-          attackers |= attacks_bb<BISHOP>(to, occupied) & (bb[BISHOP] | bb[QUEEN]);
+  occupied ^= b & ~(b - 1);
 
-      if (Pt == ROOK || Pt == QUEEN)
-          attackers |= attacks_bb<ROOK>(to, occupied) & (bb[ROOK] | bb[QUEEN]);
+  if (Pt == PAWN || Pt == BISHOP || Pt == QUEEN)
+      attackers |= attacks_bb<BISHOP>(to, occupied) & (bb[BISHOP] | bb[QUEEN]);
 
-      attackers &= occupied; // Remove the just found attacker
+  if (Pt == ROOK || Pt == QUEEN)
+      attackers |= attacks_bb<ROOK>(to, occupied) & (bb[ROOK] | bb[QUEEN]);
 
-      return (PieceType)Pt;
-  }
-  return min_attacker<Pt+1>(bb, to, stmAttackers, occupied, attackers);
+  attackers &= occupied; // After X-ray that may add already processed pieces
+  return (PieceType)Pt;
 }
 
 template<> FORCE_INLINE
@@ -395,16 +392,18 @@ const string Position::pretty(Move move) const {
 
   string brd = twoRows + twoRows + twoRows + twoRows + dottedLine;
 
+  for (Bitboard b = pieces(); b; )
+  {
+      Square s = pop_lsb(&b);
+      brd[513 - 68 * rank_of(s) + 4 * file_of(s)] = PieceToChar[piece_on(s)];
+  }
+
   std::ostringstream ss;
 
   if (move)
       ss << "\nMove: " << (sideToMove == BLACK ? ".." : "")
          << move_to_san(*const_cast<Position*>(this), move);
 
-  for (Square sq = SQ_A1; sq <= SQ_H8; sq++)
-      if (piece_on(sq) != NO_PIECE)
-          brd[513 - 68*rank_of(sq) + 4*file_of(sq)] = PieceToChar[piece_on(sq)];
-
   ss << brd << "\nFen: " << fen() << "\nKey: " << std::hex << std::uppercase
      << std::setfill('0') << std::setw(16) << st->key << "\nCheckers: ";
 
@@ -545,7 +544,7 @@ bool Position::is_pseudo_legal(const Move m) const {
       return false;
 
   // The destination square cannot be occupied by a friendly piece
-  if (piece_on(to) != NO_PIECE && color_of(piece_on(to)) == us)
+  if (pieces(us) & to)
       return false;
 
   // Handle the special case of a pawn move
@@ -655,7 +654,7 @@ bool Position::move_gives_check(Move m, const CheckInfo& ci) const {
       return true;
 
   // Discovery check ?
-  if (ci.dcCandidates && (ci.dcCandidates & from))
+  if (unlikely(ci.dcCandidates) && (ci.dcCandidates & from))
   {
       // For pawn and king moves we need to verify also direction
       if (   (pt != PAWN && pt != KING)
@@ -1136,7 +1135,7 @@ int Position::see_sign(Move m) const {
   // Early return if SEE cannot be negative because captured piece value
   // is not less then capturing one. Note that king moves always return
   // here because king midgame value is set to 0.
-  if (PieceValue[MG][piece_on(to_sq(m))] >= PieceValue[MG][piece_moved(m)])
+  if (PieceValue[MG][piece_moved(m)] <= PieceValue[MG][piece_on(to_sq(m))])
       return 1;
 
   return see(m);
@@ -1154,36 +1153,31 @@ int Position::see(Move m, int asymmThreshold) const {
 
   from = from_sq(m);
   to = to_sq(m);
-  captured = type_of(piece_on(to));
+  swapList[0] = PieceValue[MG][type_of(piece_on(to))];
+  stm = color_of(piece_on(from));
   occupied = pieces() ^ from;
 
-  // Handle en passant moves
+  // Castle moves are implemented as king capturing the rook so cannot be
+  // handled correctly. Simply return 0 that is always the correct value
+  // unless in the rare case the rook ends up under attack.
+  if (type_of(m) == CASTLE)
+      return 0;
+
   if (type_of(m) == ENPASSANT)
   {
-      Square capQq = to - pawn_push(sideToMove);
-
-      assert(!captured);
-      assert(type_of(piece_on(capQq)) == PAWN);
-
-      // Remove the captured pawn
-      occupied ^= capQq;
-      captured = PAWN;
+      occupied ^= to - pawn_push(stm); // Remove the captured pawn
+      swapList[0] = PieceValue[MG][PAWN];
   }
-  else if (type_of(m) == CASTLE)
-      // Castle moves are implemented as king capturing the rook so cannot be
-      // handled correctly. Simply return 0 that is always the correct value
-      // unless the rook is ends up under attack.
-      return 0;
 
   // Find all attackers to the destination square, with the moving piece
   // removed, but possibly an X-ray attacker added behind it.
-  attackers = attackers_to(to, occupied);
+  attackers = attackers_to(to, occupied) & occupied;
 
   // If the opponent has no attackers we are finished
-  stm = ~color_of(piece_on(from));
+  stm = ~stm;
   stmAttackers = attackers & pieces(stm);
   if (!stmAttackers)
-      return PieceValue[MG][captured];
+      return swapList[0];
 
   // The destination square is defended, which makes things rather more
   // difficult to compute. We proceed by building up a "swap list" containing
@@ -1191,7 +1185,6 @@ int Position::see(Move m, int asymmThreshold) const {
   // destination square, where the sides alternately capture, and always
   // capture with the least valuable piece. After each capture, we look for
   // new X-ray attacks from behind the capturing piece.
-  swapList[0] = PieceValue[MG][captured];
   captured = type_of(piece_on(from));
 
   do {
@@ -1206,12 +1199,10 @@ int Position::see(Move m, int asymmThreshold) const {
       stm = ~stm;
       stmAttackers = attackers & pieces(stm);
 
-      if (captured == KING)
+      // Stop before processing a king capture
+      if (captured == KING && stmAttackers)
       {
-          // Stop before processing a king capture
-          if (stmAttackers)
-              swapList[slIndex++] = QueenValueMg * 16;
-
+          swapList[slIndex++] = QueenValueMg * 16;
           break;
       }