X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fposition.cpp;h=e8689ea727316d8f474abcd679999f2326826de6;hp=f055b04c9a6563a6f243464e2cd90c1ea9a6a5d7;hb=9cdca7516c9397f991b2c0194f5de1ade26622e8;hpb=456f37b8aba74018fc532099c13a9af4e6714867 diff --git a/src/position.cpp b/src/position.cpp index f055b04c..e8689ea7 100644 --- a/src/position.cpp +++ b/src/position.cpp @@ -25,6 +25,7 @@ #include "bitcount.h" #include "movegen.h" +#include "notation.h" #include "position.h" #include "psqtab.h" #include "rkiss.h" @@ -35,35 +36,101 @@ using std::string; using std::cout; using std::endl; -Key Position::zobrist[2][8][64]; -Key Position::zobEp[8]; -Key Position::zobCastle[16]; -Key Position::zobSideToMove; -Key Position::zobExclusion; - -Score Position::pieceSquareTable[16][64]; - -// 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 -}; - -// To convert a Piece to and from a FEN char -static const string PieceToChar(" PNBRQK pnbrqk ."); +static const string PieceToChar(" PNBRQK pnbrqk"); + +CACHE_LINE_ALIGNMENT + +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 enpassant[8]; // [file] +Key castle[16]; // [castleRight] +Key side; +Key exclusion; + +/// init() initializes at startup the various arrays used to compute hash keys +/// and the piece square tables. The latter is a two-step operation: First, the +/// white halves of the tables are copied from PSQT[] tables. Second, the black +/// halves of the tables are initialized by flipping and changing the sign of +/// the white scores. + +void init() { + + RKISS rk; + + for (Color c = WHITE; c <= BLACK; c++) + for (PieceType pt = PAWN; pt <= KING; pt++) + for (Square s = SQ_A1; s <= SQ_H8; s++) + psq[c][pt][s] = rk.rand(); + + for (File f = FILE_A; f <= FILE_H; f++) + enpassant[f] = rk.rand(); + + for (int cr = CASTLES_NONE; cr <= ALL_CASTLES; cr++) + { + Bitboard b = cr; + while (b) + { + Key k = castle[1ULL << pop_lsb(&b)]; + castle[cr] ^= k ? k : rk.rand(); + } + } + + side = rk.rand(); + exclusion = rk.rand(); + + for (PieceType pt = PAWN; pt <= KING; 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++) + { + pieceSquareTable[make_piece(WHITE, pt)][ s] = (v + PSQT[pt][s]); + pieceSquareTable[make_piece(BLACK, pt)][~s] = -(v + PSQT[pt][s]); + } + } +} + +} // namespace Zobrist + + +/// 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 static FORCE_INLINE +PieceType next_attacker(const Bitboard* bb, const Square& to, const Bitboard& stmAttackers, + Bitboard& occupied, Bitboard& attackers) { + + const PieceType NextPt = PieceType((int)Pt + 1); + + if (!(stmAttackers & bb[Pt])) + return next_attacker(bb, to, stmAttackers, occupied, attackers); + + 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 Pt; +} + +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 +} /// CheckInfo c'tor @@ -89,7 +156,7 @@ CheckInfo::CheckInfo(const Position& pos) { /// object do not depend on any external data so we detach state pointer from /// the source one. -void Position::operator=(const Position& pos) { +Position& Position::operator=(const Position& pos) { memcpy(this, &pos, sizeof(Position)); startState = *st; @@ -97,6 +164,8 @@ void Position::operator=(const Position& pos) { nodes = 0; assert(pos_is_ok()); + + return *this; } @@ -154,7 +223,7 @@ void Position::from_fen(const string& fenStr, bool isChess960, Thread* th) { sq += Square(token - '0'); // Advance the given number of files else if (token == '/') - sq = make_square(FILE_A, rank_of(sq) - Rank(2)); + sq -= Square(16); else if ((p = PieceToChar.find(token)) != string::npos) { @@ -187,7 +256,7 @@ void Position::from_fen(const string& fenStr, bool isChess960, Thread* th) { for (rsq = relative_square(c, SQ_A1); type_of(piece_on(rsq)) != ROOK; rsq++) {} else if (token >= 'A' && token <= 'H') - rsq = make_square(File(token - 'A'), relative_rank(c, RANK_1)); + rsq = File(token - 'A') | relative_rank(c, RANK_1); else continue; @@ -199,9 +268,9 @@ void Position::from_fen(const string& fenStr, bool isChess960, Thread* th) { if ( ((fen >> col) && (col >= 'a' && col <= 'h')) && ((fen >> row) && (row == '3' || row == '6'))) { - st->epSquare = make_square(File(col - 'a'), Rank(row - '1')); + st->epSquare = File(col - 'a') | Rank(row - '1'); - if (!(attackers_to(st->epSquare) & pieces(PAWN, sideToMove))) + if (!(attackers_to(st->epSquare) & pieces(sideToMove, PAWN))) st->epSquare = SQ_NONE; } @@ -268,7 +337,7 @@ const string Position::to_fen() const { for (File file = FILE_A; file <= FILE_H; file++) { - sq = make_square(file, rank); + sq = file | rank; if (is_empty(sq)) emptyCnt++; @@ -319,7 +388,13 @@ const string Position::to_fen() const { void Position::print(Move move) const { - const char* dottedLine = "\n+---+---+---+---+---+---+---+---+\n"; + const string dottedLine = "\n+---+---+---+---+---+---+---+---+"; + const string twoRows = dottedLine + "\n| | . | | . | | . | | . |" + + dottedLine + "\n| . | | . | | . | | . | |"; + + string brd = twoRows + twoRows + twoRows + twoRows + dottedLine; + + sync_cout; if (move) { @@ -327,22 +402,11 @@ void Position::print(Move move) const { cout << "\nMove is: " << (sideToMove == BLACK ? ".." : "") << move_to_san(p, move); } - for (Rank rank = RANK_8; rank >= RANK_1; rank--) - { - cout << dottedLine << '|'; - for (File file = FILE_A; file <= FILE_H; file++) - { - Square sq = make_square(file, rank); - Piece piece = piece_on(sq); - char c = (color_of(piece) == BLACK ? '=' : ' '); - - if (piece == NO_PIECE && !opposite_colors(sq, SQ_A1)) - piece++; // Index the dot + 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)]; - cout << c << PieceToChar[piece] << c << '|'; - } - } - cout << dottedLine << "Fen is: " << to_fen() << "\nKey is: " << st->key << endl; + cout << brd << "\nFen is: " << to_fen() << "\nKey is: " << st->key << sync_endl; } @@ -364,7 +428,7 @@ Bitboard Position::hidden_checkers() const { while (pinners) { - b = between_bb(ksq, pop_1st_bit(&pinners)) & pieces(); + b = between_bb(ksq, pop_lsb(&pinners)) & pieces(); if (b && !more_than_one(b) && (b & pieces(sideToMove))) result |= b; @@ -382,8 +446,8 @@ template Bitboard Position::hidden_checkers() const; Bitboard Position::attackers_to(Square s, Bitboard occ) const { - return (attacks_from(s, BLACK) & pieces(PAWN, WHITE)) - | (attacks_from(s, WHITE) & pieces(PAWN, BLACK)) + return (attacks_from(s, BLACK) & pieces(WHITE, PAWN)) + | (attacks_from(s, WHITE) & pieces(BLACK, PAWN)) | (attacks_from(s) & pieces(KNIGHT)) | (attacks_bb(s, occ) & pieces(ROOK, QUEEN)) | (attacks_bb(s, occ) & pieces(BISHOP, QUEEN)) @@ -431,8 +495,8 @@ bool Position::move_attacks_square(Move m, Square s) const { return true; // Scan for possible X-ray attackers behind the moved piece - xray = (attacks_bb(s, occ) & pieces(ROOK, QUEEN, color_of(piece))) - |(attacks_bb(s, occ) & pieces(BISHOP, QUEEN, color_of(piece))); + xray = (attacks_bb< ROOK>(s, occ) & pieces(color_of(piece), QUEEN, ROOK)) + | (attacks_bb(s, occ) & pieces(color_of(piece), QUEEN, BISHOP)); // Verify attackers are triggered by our move and not already existing return xray && (xray ^ (xray & attacks_from(s))); @@ -455,7 +519,7 @@ bool Position::pl_move_is_legal(Move m, Bitboard pinned) const { // En passant captures are a tricky special case. Because they are rather // uncommon, we do it simply by testing whether the king is attacked after // the move is made. - if (is_enpassant(m)) + if (type_of(m) == ENPASSANT) { Color them = ~us; Square to = to_sq(m); @@ -468,15 +532,15 @@ bool Position::pl_move_is_legal(Move m, Bitboard pinned) const { assert(piece_on(capsq) == make_piece(them, PAWN)); assert(piece_on(to) == NO_PIECE); - return !(attacks_bb(ksq, b) & pieces(ROOK, QUEEN, them)) - && !(attacks_bb(ksq, b) & pieces(BISHOP, QUEEN, them)); + return !(attacks_bb< ROOK>(ksq, b) & pieces(them, QUEEN, ROOK)) + && !(attacks_bb(ksq, b) & pieces(them, QUEEN, BISHOP)); } // If the moving piece is a king, check whether the destination // square is attacked by the opponent. Castling moves are checked // for legality during move generation. if (type_of(piece_on(from)) == KING) - return is_castle(m) || !(attackers_to(to_sq(m)) & pieces(~us)); + return type_of(m) == CASTLE || !(attackers_to(to_sq(m)) & pieces(~us)); // A non-king move is legal if and only if it is not pinned or it // is moving along the ray towards or away from the king. @@ -492,7 +556,7 @@ bool Position::pl_move_is_legal(Move m, Bitboard pinned) const { bool Position::move_is_legal(const Move m) const { - for (MoveList ml(*this); !ml.end(); ++ml) + for (MoveList ml(*this); !ml.end(); ++ml) if (ml.move() == m) return true; @@ -513,7 +577,7 @@ bool Position::is_pseudo_legal(const Move m) const { Piece pc = piece_moved(m); // Use a slower but simpler function for uncommon cases - if (is_special(m)) + if (type_of(m) != NORMAL) return move_is_legal(m); // Is not a promotion, so promotion piece must be empty @@ -602,7 +666,7 @@ bool Position::is_pseudo_legal(const Move m) const { if (type_of(pc) != KING) { Bitboard b = checkers(); - Square checksq = pop_1st_bit(&b); + Square checksq = pop_lsb(&b); if (b) // double check ? In this case a king move is required return false; @@ -641,37 +705,37 @@ bool Position::move_gives_check(Move m, const CheckInfo& ci) const { if (ci.dcCandidates && (ci.dcCandidates & from)) { // For pawn and king moves we need to verify also direction - if ( (pt != PAWN && pt != KING) + if ( (pt != PAWN && pt != KING) || !squares_aligned(from, to, king_square(~sideToMove))) return true; } // Can we skip the ugly special cases ? - if (!is_special(m)) + if (type_of(m) == NORMAL) return false; Color us = sideToMove; Square ksq = king_square(~us); // Promotion with check ? - if (is_promotion(m)) + if (type_of(m) == PROMOTION) return attacks_from(Piece(promotion_type(m)), to, pieces() ^ from) & ksq; // En passant capture with check ? We have already handled the case // of direct checks and ordinary discovered check, the only case we // need to handle is the unusual case of a discovered check through // the captured pawn. - if (is_enpassant(m)) + if (type_of(m) == ENPASSANT) { - Square capsq = make_square(file_of(to), rank_of(from)); + Square capsq = file_of(to) | rank_of(from); Bitboard b = (pieces() ^ from ^ capsq) | to; - return (attacks_bb< ROOK>(ksq, b) & pieces( ROOK, QUEEN, us)) - | (attacks_bb(ksq, b) & pieces(BISHOP, QUEEN, us)); + return (attacks_bb< ROOK>(ksq, b) & pieces(us, QUEEN, ROOK)) + | (attacks_bb(ksq, b) & pieces(us, QUEEN, BISHOP)); } // Castling with check ? - if (is_castle(m)) + if (type_of(m) == CASTLE) { Square kfrom = from; Square rfrom = to; // 'King captures the rook' notation @@ -707,28 +771,20 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI // Copy some fields of old state to our new StateInfo object except the ones // which are recalculated from scratch anyway, then switch our state pointer // to point to the new, ready to be updated, state. - struct ReducedStateInfo { - Key pawnKey, materialKey; - Value npMaterial[2]; - int castleRights, rule50, pliesFromNull; - Score psq_score; - Square epSquare; - }; - memcpy(&newSt, st, sizeof(ReducedStateInfo)); newSt.previous = st; st = &newSt; // Update side to move - k ^= zobSideToMove; + k ^= Zobrist::side; // Increment the 50 moves rule draw counter. Resetting it to zero in the // case of a capture or a pawn move is taken care of later. st->rule50++; st->pliesFromNull++; - if (is_castle(m)) + if (type_of(m) == CASTLE) { st->key = k; do_castle_move(m); @@ -741,7 +797,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI Square to = to_sq(m); Piece piece = piece_on(from); PieceType pt = type_of(piece); - PieceType capture = is_enpassant(m) ? PAWN : type_of(piece_on(to)); + PieceType capture = type_of(m) == ENPASSANT ? PAWN : type_of(piece_on(to)); assert(color_of(piece) == us); assert(color_of(piece_on(to)) != us); @@ -755,7 +811,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI // update non-pawn material. if (capture == PAWN) { - if (is_enpassant(m)) + if (type_of(m) == ENPASSANT) { capsq += pawn_push(them); @@ -768,10 +824,10 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI board[capsq] = NO_PIECE; } - st->pawnKey ^= zobrist[them][PAWN][capsq]; + 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; @@ -791,8 +847,8 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI pieceList[them][capture][pieceCount[them][capture]] = SQ_NONE; // Update hash keys - k ^= zobrist[them][capture][capsq]; - st->materialKey ^= zobrist[them][capture][pieceCount[them][capture]]; + k ^= Zobrist::psq[them][capture][capsq]; + st->materialKey ^= Zobrist::psq[them][capture][pieceCount[them][capture]]; // Update incremental scores st->psqScore -= pieceSquareTable[make_piece(them, capture)][capsq]; @@ -802,12 +858,12 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI } // Update hash key - k ^= zobrist[us][pt][from] ^ zobrist[us][pt][to]; + k ^= Zobrist::psq[us][pt][from] ^ Zobrist::psq[us][pt][to]; // Reset en passant square if (st->epSquare != SQ_NONE) { - k ^= zobEp[file_of(st->epSquare)]; + k ^= Zobrist::enpassant[file_of(st->epSquare)]; st->epSquare = SQ_NONE; } @@ -815,7 +871,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI if (st->castleRights && (castleRightsMask[from] | castleRightsMask[to])) { int cr = castleRightsMask[from] | castleRightsMask[to]; - k ^= zobCastle[st->castleRights & cr]; + k ^= Zobrist::castle[st->castleRights & cr]; st->castleRights &= ~cr; } @@ -841,13 +897,13 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI { // Set en-passant square, only if moved pawn can be captured if ( (int(to) ^ int(from)) == 16 - && (attacks_from(from + pawn_push(us), us) & pieces(PAWN, them))) + && (attacks_from(from + pawn_push(us), us) & pieces(them, PAWN))) { st->epSquare = Square((from + to) / 2); - k ^= zobEp[file_of(st->epSquare)]; + k ^= Zobrist::enpassant[file_of(st->epSquare)]; } - if (is_promotion(m)) + if (type_of(m) == PROMOTION) { PieceType promotion = promotion_type(m); @@ -869,21 +925,21 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI pieceList[us][promotion][index[to]] = to; // Update hash keys - k ^= zobrist[us][PAWN][to] ^ zobrist[us][promotion][to]; - st->pawnKey ^= zobrist[us][PAWN][to]; - st->materialKey ^= zobrist[us][promotion][pieceCount[us][promotion]++] - ^ zobrist[us][PAWN][pieceCount[us][PAWN]]; + k ^= Zobrist::psq[us][PAWN][to] ^ Zobrist::psq[us][promotion][to]; + st->pawnKey ^= Zobrist::psq[us][PAWN][to]; + st->materialKey ^= Zobrist::psq[us][promotion][pieceCount[us][promotion]++] + ^ Zobrist::psq[us][PAWN][pieceCount[us][PAWN]]; // Update incremental score st->psqScore += pieceSquareTable[make_piece(us, promotion)][to] - pieceSquareTable[make_piece(us, PAWN)][to]; // Update material - st->npMaterial[us] += PieceValueMidgame[promotion]; + st->npMaterial[us] += PieceValue[Mg][promotion]; } // Update pawn hash key - st->pawnKey ^= zobrist[us][PAWN][from] ^ zobrist[us][PAWN][to]; + st->pawnKey ^= Zobrist::psq[us][PAWN][from] ^ Zobrist::psq[us][PAWN][to]; // Reset rule 50 draw counter st->rule50 = 0; @@ -907,7 +963,7 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI if (moveIsCheck) { - if (is_special(m)) + if (type_of(m) != NORMAL) st->checkersBB = attackers_to(king_square(them)) & pieces(us); else { @@ -919,10 +975,10 @@ void Position::do_move(Move m, StateInfo& newSt, const CheckInfo& ci, bool moveI if (ci.dcCandidates && (ci.dcCandidates & from)) { if (pt != ROOK) - st->checkersBB |= attacks_from(king_square(them)) & pieces(ROOK, QUEEN, us); + st->checkersBB |= attacks_from(king_square(them)) & pieces(us, QUEEN, ROOK); if (pt != BISHOP) - st->checkersBB |= attacks_from(king_square(them)) & pieces(BISHOP, QUEEN, us); + st->checkersBB |= attacks_from(king_square(them)) & pieces(us, QUEEN, BISHOP); } } } @@ -942,7 +998,7 @@ void Position::undo_move(Move m) { sideToMove = ~sideToMove; - if (is_castle(m)) + if (type_of(m) == CASTLE) { do_castle_move(m); return; @@ -960,7 +1016,7 @@ void Position::undo_move(Move m) { assert(color_of(piece) == us); assert(capture != KING); - if (is_promotion(m)) + if (type_of(m) == PROMOTION) { PieceType promotion = promotion_type(m); @@ -1003,7 +1059,7 @@ void Position::undo_move(Move m) { { Square capsq = to; - if (is_enpassant(m)) + if (type_of(m) == ENPASSANT) { capsq -= pawn_push(us); @@ -1040,7 +1096,7 @@ template void Position::do_castle_move(Move m) { assert(is_ok(m)); - assert(is_castle(m)); + assert(type_of(m) == CASTLE); Square kto, kfrom, rfrom, rto, kAfter, rAfter; @@ -1101,18 +1157,18 @@ void Position::do_castle_move(Move m) { st->psqScore += psq_delta(rook, rfrom, rto); // Update hash key - st->key ^= zobrist[us][KING][kfrom] ^ zobrist[us][KING][kto]; - st->key ^= zobrist[us][ROOK][rfrom] ^ zobrist[us][ROOK][rto]; + st->key ^= Zobrist::psq[us][KING][kfrom] ^ Zobrist::psq[us][KING][kto]; + st->key ^= Zobrist::psq[us][ROOK][rfrom] ^ Zobrist::psq[us][ROOK][rto]; // Clear en passant square if (st->epSquare != SQ_NONE) { - st->key ^= zobEp[file_of(st->epSquare)]; + st->key ^= Zobrist::enpassant[file_of(st->epSquare)]; st->epSquare = SQ_NONE; } // Update castling rights - st->key ^= zobCastle[st->castleRights & castleRightsMask[kfrom]]; + st->key ^= Zobrist::castle[st->castleRights & castleRightsMask[kfrom]]; st->castleRights &= ~castleRightsMask[kfrom]; // Update checkers BB @@ -1153,9 +1209,9 @@ void Position::do_null_move(StateInfo& backupSt) { if (Do) { if (st->epSquare != SQ_NONE) - st->key ^= zobEp[file_of(st->epSquare)]; + st->key ^= Zobrist::enpassant[file_of(st->epSquare)]; - st->key ^= zobSideToMove; + st->key ^= Zobrist::side; prefetch((char*)TT.first_entry(st->key)); st->epSquare = SQ_NONE; @@ -1184,7 +1240,7 @@ 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); @@ -1193,47 +1249,45 @@ 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 (is_castle(m)) - 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 (is_enpassant(m)) + 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 @@ -1241,43 +1295,31 @@ 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 && stmAttackers) { assert(slIndex < 32); - swapList[slIndex++] = QueenValueMidgame*10; + swapList[slIndex++] = QueenValueMg * 16; break; } + } while (stmAttackers); // Having built the swap list, we negamax through it to find the best @@ -1332,19 +1374,19 @@ void Position::put_piece(Piece p, Square s) { Key Position::compute_key() const { - Key k = zobCastle[st->castleRights]; + Key k = Zobrist::castle[st->castleRights]; for (Bitboard b = pieces(); b; ) { - Square s = pop_1st_bit(&b); - k ^= zobrist[color_of(piece_on(s))][type_of(piece_on(s))][s]; + Square s = pop_lsb(&b); + k ^= Zobrist::psq[color_of(piece_on(s))][type_of(piece_on(s))][s]; } if (ep_square() != SQ_NONE) - k ^= zobEp[file_of(ep_square())]; + k ^= Zobrist::enpassant[file_of(ep_square())]; if (sideToMove == BLACK) - k ^= zobSideToMove; + k ^= Zobrist::side; return k; } @@ -1362,8 +1404,8 @@ Key Position::compute_pawn_key() const { for (Bitboard b = pieces(PAWN); b; ) { - Square s = pop_1st_bit(&b); - k ^= zobrist[color_of(piece_on(s))][PAWN][s]; + Square s = pop_lsb(&b); + k ^= Zobrist::psq[color_of(piece_on(s))][PAWN][s]; } return k; @@ -1383,7 +1425,7 @@ Key Position::compute_material_key() const { for (Color c = WHITE; c <= BLACK; c++) for (PieceType pt = PAWN; pt <= QUEEN; pt++) for (int cnt = 0; cnt < piece_count(c, pt); cnt++) - k ^= zobrist[c][pt][cnt]; + k ^= Zobrist::psq[c][pt][cnt]; return k; } @@ -1399,7 +1441,7 @@ Score Position::compute_psq_score() const { for (Bitboard b = pieces(); b; ) { - Square s = pop_1st_bit(&b); + Square s = pop_lsb(&b); score += pieceSquareTable[piece_on(s)][s]; } @@ -1417,7 +1459,7 @@ 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; } @@ -1431,11 +1473,11 @@ 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? - if (st->rule50 > 99 && (!in_check() || MoveList(*this).size())) + if (st->rule50 > 99 && (!in_check() || MoveList(*this).size())) return true; // Draw by repetition? @@ -1467,50 +1509,6 @@ template bool Position::is_draw() const; template bool Position::is_draw() const; -/// Position::init() is a static member function which initializes at startup -/// the various arrays used to compute hash keys and the piece square tables. -/// The latter is a two-step operation: First, the white halves of the tables -/// are copied from PSQT[] tables. Second, the black halves of the tables are -/// initialized by flipping and changing the sign of the white scores. - -void Position::init() { - - RKISS rk; - - for (Color c = WHITE; c <= BLACK; c++) - for (PieceType pt = PAWN; pt <= KING; pt++) - for (Square s = SQ_A1; s <= SQ_H8; s++) - zobrist[c][pt][s] = rk.rand(); - - for (File f = FILE_A; f <= FILE_H; f++) - zobEp[f] = rk.rand(); - - for (int cr = CASTLES_NONE; cr <= ALL_CASTLES; cr++) - { - Bitboard b = cr; - while (b) - { - Key k = zobCastle[1ULL << pop_1st_bit(&b)]; - zobCastle[cr] ^= k ? k : rk.rand(); - } - } - - zobSideToMove = rk.rand(); - zobExclusion = rk.rand(); - - for (PieceType pt = PAWN; pt <= KING; pt++) - { - Score v = make_score(PieceValueMidgame[pt], PieceValueEndgame[pt]); - - for (Square s = SQ_A1; s <= SQ_H8; s++) - { - pieceSquareTable[make_piece(WHITE, pt)][ s] = (v + PSQT[pt][s]); - pieceSquareTable[make_piece(BLACK, pt)][~s] = -(v + PSQT[pt][s]); - } - } -} - - /// Position::flip() flips position with the white and black sides reversed. This /// is only useful for debugging especially for finding evaluation symmetry bugs. @@ -1651,7 +1649,7 @@ bool Position::pos_is_ok(int* failedStep) const { if ((*step)++, debugPieceCounts) for (Color c = WHITE; c <= BLACK; c++) for (PieceType pt = PAWN; pt <= KING; pt++) - if (pieceCount[c][pt] != popcount(pieces(pt, c))) + if (pieceCount[c][pt] != popcount(pieces(c, pt))) return false; if ((*step)++, debugPieceList)