X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=4bc8df597e8e02e1af5cf309b1f2b82d68c1bd7a;hp=60bdeafb4ca7d6b4e2d5db620b61cdf76f852ab9;hb=55bd27b8f08a151128d7065fa2819aa3e9605299;hpb=7c8b7222f5eea024ab480abb2d9289fd1e42da9c diff --git a/src/position.cpp b/src/position.cpp index 60bdeafb..4bc8df59 100644 --- a/src/position.cpp +++ b/src/position.cpp @@ -36,35 +36,18 @@ using std::string; using std::cout; using std::endl; -// To convert a Piece to and from a FEN char static const string PieceToChar(" PNBRQK pnbrqk"); -// Material values arrays, indexed by Piece -const Value PieceValueMidgame[17] = { - VALUE_ZERO, - PawnValueMidgame, KnightValueMidgame, BishopValueMidgame, - RookValueMidgame, QueenValueMidgame, - VALUE_ZERO, VALUE_ZERO, VALUE_ZERO, - PawnValueMidgame, KnightValueMidgame, BishopValueMidgame, - RookValueMidgame, QueenValueMidgame -}; - -const Value PieceValueEndgame[17] = { - VALUE_ZERO, - PawnValueEndgame, KnightValueEndgame, BishopValueEndgame, - RookValueEndgame, QueenValueEndgame, - VALUE_ZERO, VALUE_ZERO, VALUE_ZERO, - PawnValueEndgame, KnightValueEndgame, BishopValueEndgame, - RookValueEndgame, QueenValueEndgame -}; - CACHE_LINE_ALIGNMENT -Score pieceSquareTable[16][64]; +Score pieceSquareTable[16][64]; // [piece][square] +Value PieceValue[2][18] = { // [Mg / Eg][piece / pieceType] +{ VALUE_ZERO, PawnValueMg, KnightValueMg, BishopValueMg, RookValueMg, QueenValueMg }, +{ VALUE_ZERO, PawnValueEg, KnightValueEg, BishopValueEg, RookValueEg, QueenValueEg } }; namespace Zobrist { -Key psq[2][8][64]; // [color][pieceType][square]/[piece count] +Key psq[2][8][64]; // [color][pieceType][square / piece count] Key enpassant[8]; // [file] Key castle[16]; // [castleRight] Key side; @@ -103,7 +86,10 @@ void init() { for (PieceType pt = PAWN; pt <= KING; pt++) { - Score v = make_score(PieceValueMidgame[pt], PieceValueEndgame[pt]); + PieceValue[Mg][make_piece(BLACK, pt)] = PieceValue[Mg][pt]; + PieceValue[Eg][make_piece(BLACK, pt)] = PieceValue[Eg][pt]; + + Score v = make_score(PieceValue[Mg][pt], PieceValue[Eg][pt]); for (Square s = SQ_A1; s <= SQ_H8; s++) { @@ -116,6 +102,40 @@ void init() { } // namespace Zobrist +namespace { + +/// next_attacker() is an helper function used by see() to locate the least +/// valuable attacker for the side to move, remove the attacker we just found +/// from the 'occupied' bitboard and scan for new X-ray attacks behind it. + +template FORCE_INLINE +PieceType next_attacker(const Bitboard* bb, const Square& to, const Bitboard& stmAttackers, + Bitboard& occupied, Bitboard& attackers) { + + if (stmAttackers & bb[Pt]) + { + Bitboard b = stmAttackers & bb[Pt]; + occupied ^= b & ~(b - 1); + + if (Pt == PAWN || Pt == BISHOP || Pt == QUEEN) + attackers |= attacks_bb(to, occupied) & (bb[BISHOP] | bb[QUEEN]); + + if (Pt == ROOK || Pt == QUEEN) + attackers |= attacks_bb(to, occupied) & (bb[ROOK] | bb[QUEEN]); + + return (PieceType)Pt; + } + return next_attacker(bb, to, stmAttackers, occupied, attackers); +} + +template<> FORCE_INLINE +PieceType next_attacker(const Bitboard*, const Square&, const Bitboard&, Bitboard&, Bitboard&) { + return KING; // No need to update bitboards, it is the last cycle +} + +} // namespace + + /// CheckInfo c'tor CheckInfo::CheckInfo(const Position& pos) { @@ -377,6 +397,8 @@ void Position::print(Move move) const { string brd = twoRows + twoRows + twoRows + twoRows + dottedLine; + sync_cout; + if (move) { Position p(*this); @@ -387,7 +409,7 @@ void Position::print(Move move) const { if (piece_on(sq) != NO_PIECE) brd[513 - 68*rank_of(sq) + 4*file_of(sq)] = PieceToChar[piece_on(sq)]; - cout << brd << "\nFen is: " << to_fen() << "\nKey is: " << st->key << endl; + cout << brd << "\nFen is: " << to_fen() << "\nKey is: " << st->key << sync_endl; } @@ -808,7 +830,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI st->pawnKey ^= Zobrist::psq[them][PAWN][capsq]; } else - st->npMaterial[them] -= PieceValueMidgame[capture]; + st->npMaterial[them] -= PieceValue[Mg][capture]; // Remove the captured piece byTypeBB[ALL_PIECES] ^= capsq; @@ -916,7 +938,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI - pieceSquareTable[make_piece(us, PAWN)][to]; // Update material - st->npMaterial[us] += PieceValueMidgame[promotion]; + st->npMaterial[us] += PieceValue[Mg][promotion]; } // Update pawn hash key @@ -1221,7 +1243,7 @@ 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 (PieceValueMidgame[piece_on(to_sq(m))] >= PieceValueMidgame[piece_moved(m)]) + if (PieceValue[Mg][piece_on(to_sq(m))] >= PieceValue[Mg][piece_moved(m)]) return 1; return see(m); @@ -1230,47 +1252,45 @@ int Position::see_sign(Move m) const { int Position::see(Move m) const { Square from, to; - Bitboard occ, attackers, stmAttackers, b; + Bitboard occupied, attackers, stmAttackers; int swapList[32], slIndex = 1; - PieceType capturedType, pt; + PieceType captured; Color stm; assert(is_ok(m)); - // As castle moves are implemented as capturing the rook, they have - // SEE == RookValueMidgame most of the times (unless the rook is under - // attack). - if (type_of(m) == CASTLE) - return 0; - from = from_sq(m); to = to_sq(m); - capturedType = type_of(piece_on(to)); - occ = pieces(); + captured = type_of(piece_on(to)); + occupied = pieces() ^ from; // Handle en passant moves if (type_of(m) == ENPASSANT) { Square capQq = to - pawn_push(sideToMove); - assert(!capturedType); + assert(!captured); assert(type_of(piece_on(capQq)) == PAWN); // Remove the captured pawn - occ ^= capQq; - capturedType = PAWN; + occupied ^= capQq; + captured = 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. - occ ^= from; - attackers = attackers_to(to, occ); + attackers = attackers_to(to, occupied); // If the opponent has no attackers we are finished stm = ~color_of(piece_on(from)); stmAttackers = attackers & pieces(stm); if (!stmAttackers) - return PieceValueMidgame[capturedType]; + return PieceValue[Mg][captured]; // The destination square is defended, which makes things rather more // difficult to compute. We proceed by building up a "swap list" containing @@ -1278,43 +1298,32 @@ int Position::see(Move m) 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] = PieceValueMidgame[capturedType]; - capturedType = type_of(piece_on(from)); + swapList[0] = PieceValue[Mg][captured]; + captured = type_of(piece_on(from)); do { - // Locate the least valuable attacker for the side to move. The loop - // below looks like it is potentially infinite, but it isn't. We know - // that the side to move still has at least one attacker left. - for (pt = PAWN; !(stmAttackers & pieces(pt)); pt++) - assert(pt < KING); - - // Remove the attacker we just found from the 'occupied' bitboard, - // and scan for new X-ray attacks behind the attacker. - b = stmAttackers & pieces(pt); - occ ^= (b & (~b + 1)); - attackers |= (attacks_bb(to, occ) & pieces(ROOK, QUEEN)) - | (attacks_bb(to, occ) & pieces(BISHOP, QUEEN)); - - attackers &= occ; // Cut out pieces we've already done + assert(slIndex < 32); // Add the new entry to the swap list - assert(slIndex < 32); - swapList[slIndex] = -swapList[slIndex - 1] + PieceValueMidgame[capturedType]; + swapList[slIndex] = -swapList[slIndex - 1] + PieceValue[Mg][captured]; slIndex++; - // Remember the value of the capturing piece, and change the side to - // move before beginning the next iteration. - capturedType = pt; + // Locate and remove from 'occupied' the next least valuable attacker + captured = next_attacker(byTypeBB, to, stmAttackers, occupied, attackers); + + attackers &= occupied; // Remove the just found attacker stm = ~stm; stmAttackers = attackers & pieces(stm); - // Stop before processing a king capture - if (capturedType == KING && stmAttackers) + if (captured == KING) { - assert(slIndex < 32); - swapList[slIndex++] = QueenValueMidgame*10; + // Stop before processing a king capture + if (stmAttackers) + swapList[slIndex++] = QueenValueMg * 16; + break; } + } while (stmAttackers); // Having built the swap list, we negamax through it to find the best @@ -1454,7 +1463,7 @@ Value Position::compute_non_pawn_material(Color c) const { Value value = VALUE_ZERO; for (PieceType pt = KNIGHT; pt <= QUEEN; pt++) - value += piece_count(c, pt) * PieceValueMidgame[pt]; + value += piece_count(c, pt) * PieceValue[Mg][pt]; return value; } @@ -1468,7 +1477,7 @@ bool Position::is_draw() const { // Draw by material? if ( !pieces(PAWN) - && (non_pawn_material(WHITE) + non_pawn_material(BLACK) <= BishopValueMidgame)) + && (non_pawn_material(WHITE) + non_pawn_material(BLACK) <= BishopValueMg)) return true; // Draw by the 50 moves rule?