diff --git a/Readme.md b/Readme.md index e60ac718..823518d1 100644 --- a/Readme.md +++ b/Readme.md @@ -75,9 +75,6 @@ Currently, Stockfish has the following UCI options: Assume a time delay of x ms due to network and GUI overheads. This is useful to avoid losses on time in those cases. - * #### Minimum Thinking Time - Search for at least x ms per move. - * #### Slow Mover Lower values will make Stockfish take less time in games, higher values will make it think longer. diff --git a/src/benchmark.cpp b/src/benchmark.cpp index f338cdda..3299f373 100644 --- a/src/benchmark.cpp +++ b/src/benchmark.cpp @@ -88,7 +88,7 @@ const vector Defaults = { // Chess 960 "setoption name UCI_Chess960 value true", - "bbqnnrkr/pppppppp/8/8/8/8/PPPPPPPP/BBQNNRKR w KQkq - 0 1 moves g2g3 d7d5 d2d4 c8h3 c1g5 e8d6 g5e7 f7f6", + "bbqnnrkr/pppppppp/8/8/8/8/PPPPPPPP/BBQNNRKR w HFhf - 0 1 moves g2g3 d7d5 d2d4 c8h3 c1g5 e8d6 g5e7 f7f6", "setoption name UCI_Chess960 value false" }; diff --git a/src/bitboard.h b/src/bitboard.h index 1c598108..15ec4153 100644 --- a/src/bitboard.h +++ b/src/bitboard.h @@ -124,12 +124,19 @@ inline Bitboard operator&(Square s, Bitboard b) { return b & s; } inline Bitboard operator|(Square s, Bitboard b) { return b | s; } inline Bitboard operator^(Square s, Bitboard b) { return b ^ s; } -inline Bitboard operator|(Square s, Square s2) { return square_bb(s) | s2; } +inline Bitboard operator|(Square s1, Square s2) { return square_bb(s1) | s2; } constexpr bool more_than_one(Bitboard b) { return b & (b - 1); } +/// Counts the occupation of the bitboard depending on the occupation of SQ_A1 +/// as in `b & (1ULL << SQ_A1) ? more_than_two(b) : more_than_one(b)` + +constexpr bool conditional_more_than_two(Bitboard b) { + return b & (b - 1) & (b - 2); +} + constexpr bool opposite_colors(Square s1, Square s2) { return (s1 + rank_of(s1) + s2 + rank_of(s2)) & 1; } @@ -138,19 +145,19 @@ constexpr bool opposite_colors(Square s1, Square s2) { /// rank_bb() and file_bb() return a bitboard representing all the squares on /// the given file or rank. -inline Bitboard rank_bb(Rank r) { +constexpr Bitboard rank_bb(Rank r) { return Rank1BB << (8 * r); } -inline Bitboard rank_bb(Square s) { +constexpr Bitboard rank_bb(Square s) { return rank_bb(rank_of(s)); } -inline Bitboard file_bb(File f) { +constexpr Bitboard file_bb(File f) { return FileABB << f; } -inline Bitboard file_bb(Square s) { +constexpr Bitboard file_bb(Square s) { return file_bb(file_of(s)); } @@ -195,16 +202,16 @@ constexpr Bitboard pawn_double_attacks_bb(Bitboard b) { /// adjacent_files_bb() returns a bitboard representing all the squares on the -/// adjacent files of the given one. +/// adjacent files of a given square. -inline Bitboard adjacent_files_bb(Square s) { +constexpr Bitboard adjacent_files_bb(Square s) { return shift(file_bb(s)) | shift(file_bb(s)); } -/// line_bb(Square, Square) returns a bitboard representing an entire line, -/// from board edge to board edge, that intersects the given squares. If the -/// given squares are not on a same file/rank/diagonal, returns 0. For instance, +/// line_bb() returns a bitboard representing an entire line (from board edge +/// to board edge) that intersects the two given squares. If the given squares +/// are not on a same file/rank/diagonal, the function returns 0. For instance, /// line_bb(SQ_C4, SQ_F7) will return a bitboard with the A2-G8 diagonal. inline Bitboard line_bb(Square s1, Square s2) { @@ -215,8 +222,8 @@ inline Bitboard line_bb(Square s1, Square s2) { /// between_bb() returns a bitboard representing squares that are linearly -/// between the given squares (excluding the given squares). If the given -/// squares are not on a same file/rank/diagonal, return 0. For instance, +/// between the two given squares (excluding the given squares). If the given +/// squares are not on a same file/rank/diagonal, we return 0. For instance, /// between_bb(SQ_C4, SQ_F7) will return a bitboard with squares D5 and E6. inline Bitboard between_bb(Square s1, Square s2) { @@ -229,7 +236,7 @@ inline Bitboard between_bb(Square s1, Square s2) { /// in front of the given one, from the point of view of the given color. For instance, /// forward_ranks_bb(BLACK, SQ_D3) will return the 16 squares on ranks 1 and 2. -inline Bitboard forward_ranks_bb(Color c, Square s) { +constexpr Bitboard forward_ranks_bb(Color c, Square s) { return c == WHITE ? ~Rank1BB << 8 * relative_rank(WHITE, s) : ~Rank8BB >> 8 * relative_rank(BLACK, s); } @@ -238,7 +245,7 @@ inline Bitboard forward_ranks_bb(Color c, Square s) { /// forward_file_bb() returns a bitboard representing all the squares along the /// line in front of the given one, from the point of view of the given color. -inline Bitboard forward_file_bb(Color c, Square s) { +constexpr Bitboard forward_file_bb(Color c, Square s) { return forward_ranks_bb(c, s) & file_bb(s); } @@ -247,7 +254,7 @@ inline Bitboard forward_file_bb(Color c, Square s) { /// be attacked by a pawn of the given color when it moves along its file, starting /// from the given square. -inline Bitboard pawn_attack_span(Color c, Square s) { +constexpr Bitboard pawn_attack_span(Color c, Square s) { return forward_ranks_bb(c, s) & adjacent_files_bb(s); } @@ -255,7 +262,7 @@ inline Bitboard pawn_attack_span(Color c, Square s) { /// passed_pawn_span() returns a bitboard which can be used to test if a pawn of /// the given color and on the given square is a passed pawn. -inline Bitboard passed_pawn_span(Color c, Square s) { +constexpr Bitboard passed_pawn_span(Color c, Square s) { return pawn_attack_span(c, s) | forward_file_bb(c, s); } diff --git a/src/endgame.cpp b/src/endgame.cpp index be0755a8..40f49dce 100644 --- a/src/endgame.cpp +++ b/src/endgame.cpp @@ -181,15 +181,15 @@ Value Endgame::operator()(const Position& pos) const { assert(verify_material(pos, strongSide, RookValueMg, 0)); assert(verify_material(pos, weakSide, VALUE_ZERO, 1)); - Square strongKing = relative_square(strongSide, pos.square(strongSide)); - Square weakKing = relative_square(strongSide, pos.square(weakSide)); - Square strongRook = relative_square(strongSide, pos.square(strongSide)); - Square weakPawn = relative_square(strongSide, pos.square(weakSide)); - Square queeningSquare = make_square(file_of(weakPawn), RANK_1); + Square strongKing = pos.square(strongSide); + Square weakKing = pos.square(weakSide); + Square strongRook = pos.square(strongSide); + Square weakPawn = pos.square(weakSide); + Square queeningSquare = make_square(file_of(weakPawn), relative_rank(weakSide, RANK_8)); Value result; // If the stronger side's king is in front of the pawn, it's a win - if (forward_file_bb(WHITE, strongKing) & weakPawn) + if (forward_file_bb(strongSide, strongKing) & weakPawn) result = RookValueEg - distance(strongKing, weakPawn); // If the weaker side's king is too far from the pawn and the rook, @@ -200,15 +200,15 @@ Value Endgame::operator()(const Position& pos) const { // If the pawn is far advanced and supported by the defending king, // the position is drawish - else if ( rank_of(weakKing) <= RANK_3 + else if ( relative_rank(strongSide, weakKing) <= RANK_3 && distance(weakKing, weakPawn) == 1 - && rank_of(strongKing) >= RANK_4 + && relative_rank(strongSide, strongKing) >= RANK_4 && distance(strongKing, weakPawn) > 2 + (pos.side_to_move() == strongSide)) result = Value(80) - 8 * distance(strongKing, weakPawn); else - result = Value(200) - 8 * ( distance(strongKing, weakPawn + SOUTH) - - distance(weakKing, weakPawn + SOUTH) + result = Value(200) - 8 * ( distance(strongKing, weakPawn + pawn_push(weakSide)) + - distance(weakKing, weakPawn + pawn_push(weakSide)) - distance(weakPawn, queeningSquare)); return strongSide == pos.side_to_move() ? result : -result; diff --git a/src/evaluate.cpp b/src/evaluate.cpp index 07bed614..12ecff00 100644 --- a/src/evaluate.cpp +++ b/src/evaluate.cpp @@ -82,11 +82,11 @@ namespace { // KingAttackWeights[PieceType] contains king attack weights by piece type constexpr int KingAttackWeights[PIECE_TYPE_NB] = { 0, 0, 81, 52, 44, 10 }; - // Penalties for enemy's safe checks - constexpr int QueenSafeCheck = 772; - constexpr int RookSafeCheck = 1084; - constexpr int BishopSafeCheck = 645; - constexpr int KnightSafeCheck = 792; + // SafeCheck[PieceType][single/multiple] contains safe check bonus by piece type, + // higher if multiple safe checks are possible for that piece type. + constexpr int SafeCheck[][2] = { + {}, {}, {792, 1283}, {645, 967}, {1084, 1897}, {772, 1119} + }; #define S(mg, eg) make_score(mg, eg) @@ -108,6 +108,18 @@ namespace { S(110,182), S(114,182), S(114,192), S(116,219) } }; + // KingProtector[knight/bishop] contains penalty for each distance unit to own king + constexpr Score KingProtector[] = { S(8, 9), S(6, 9) }; + + // Outpost[knight/bishop] contains bonuses for each knight or bishop occupying a + // pawn protected square on rank 4 to 6 which is also safe from a pawn attack. + constexpr Score Outpost[] = { S(56, 36), S(30, 23) }; + + // PassedRank[Rank] contains a bonus according to the rank of a passed pawn + constexpr Score PassedRank[RANK_NB] = { + S(0, 0), S(10, 28), S(17, 33), S(15, 41), S(62, 72), S(168, 177), S(276, 260) + }; + // RookOnFile[semiopen/open] contains bonuses for each rook when there is // no (friendly) pawn on the rook file. constexpr Score RookOnFile[] = { S(19, 7), S(48, 29) }; @@ -123,23 +135,15 @@ namespace { S(0, 0), S(3, 46), S(37, 68), S(42, 60), S(0, 38), S(58, 41) }; - // PassedRank[Rank] contains a bonus according to the rank of a passed pawn - constexpr Score PassedRank[RANK_NB] = { - S(0, 0), S(10, 28), S(17, 33), S(15, 41), S(62, 72), S(168, 177), S(276, 260) - }; - // Assorted bonuses and penalties - constexpr Score BishopKingProtector = S( 6, 9); + constexpr Score BadOutpost = S( -7, 36); constexpr Score BishopOnKingRing = S( 24, 0); - constexpr Score BishopOutpost = S( 30, 23); constexpr Score BishopPawns = S( 3, 7); constexpr Score BishopXRayPawns = S( 4, 5); constexpr Score CorneredBishop = S( 50, 50); constexpr Score FlankAttacks = S( 8, 0); constexpr Score Hanging = S( 69, 36); - constexpr Score KnightKingProtector = S( 8, 9); constexpr Score KnightOnQueen = S( 16, 11); - constexpr Score KnightOutpost = S( 56, 36); constexpr Score LongDiagonalBishop = S( 45, 0); constexpr Score MinorBehindPawn = S( 18, 3); constexpr Score PassedFile = S( 11, 8); @@ -309,8 +313,14 @@ namespace { { // Bonus if piece is on an outpost square or can reach one bb = OutpostRanks & attackedBy[Us][PAWN] & ~pe->pawn_attacks_span(Them); - if (bb & s) - score += (Pt == KNIGHT) ? KnightOutpost : BishopOutpost; + if ( Pt == KNIGHT + && bb & s & ~CenterFiles + && !(b & pos.pieces(Them) & ~pos.pieces(PAWN)) + && !conditional_more_than_two( + pos.pieces(Them) & ~pos.pieces(PAWN) & (s & QueenSide ? QueenSide : KingSide))) + score += BadOutpost; + else if (bb & s) + score += Outpost[Pt == BISHOP]; else if (Pt == KNIGHT && bb & b & ~pos.pieces(Us)) score += ReachableOutpost; @@ -319,8 +329,7 @@ namespace { score += MinorBehindPawn; // Penalty if the piece is far from the king - score -= (Pt == KNIGHT ? KnightKingProtector - : BishopKingProtector) * distance(pos.square(Us), s); + score -= KingProtector[Pt == BISHOP] * distance(pos.square(Us), s); if (Pt == BISHOP) { @@ -422,41 +431,33 @@ namespace { b2 = attacks_bb(ksq, pos.pieces() ^ pos.pieces(Us, QUEEN)); // Enemy rooks checks - rookChecks = b1 & safe & attackedBy[Them][ROOK]; + rookChecks = b1 & attackedBy[Them][ROOK] & safe; if (rookChecks) - kingDanger += more_than_one(rookChecks) ? RookSafeCheck * 175/100 - : RookSafeCheck; + kingDanger += SafeCheck[ROOK][more_than_one(rookChecks)]; else unsafeChecks |= b1 & attackedBy[Them][ROOK]; - // Enemy queen safe checks: we count them only if they are from squares from - // which we can't give a rook check, because rook checks are more valuable. - queenChecks = (b1 | b2) - & attackedBy[Them][QUEEN] - & safe - & ~attackedBy[Us][QUEEN] - & ~rookChecks; + // Enemy queen safe checks: count them only if the checks are from squares from + // which opponent cannot give a rook check, because rook checks are more valuable. + queenChecks = (b1 | b2) & attackedBy[Them][QUEEN] & safe + & ~(attackedBy[Us][QUEEN] | rookChecks); if (queenChecks) - kingDanger += more_than_one(queenChecks) ? QueenSafeCheck * 145/100 - : QueenSafeCheck; + kingDanger += SafeCheck[QUEEN][more_than_one(queenChecks)]; - // Enemy bishops checks: we count them only if they are from squares from - // which we can't give a queen check, because queen checks are more valuable. - bishopChecks = b2 - & attackedBy[Them][BISHOP] - & safe + // Enemy bishops checks: count them only if they are from squares from which + // opponent cannot give a queen check, because queen checks are more valuable. + bishopChecks = b2 & attackedBy[Them][BISHOP] & safe & ~queenChecks; if (bishopChecks) - kingDanger += more_than_one(bishopChecks) ? BishopSafeCheck * 3/2 - : BishopSafeCheck; + kingDanger += SafeCheck[BISHOP][more_than_one(bishopChecks)]; + else unsafeChecks |= b2 & attackedBy[Them][BISHOP]; // Enemy knights checks knightChecks = attacks_bb(ksq) & attackedBy[Them][KNIGHT]; if (knightChecks & safe) - kingDanger += more_than_one(knightChecks & safe) ? KnightSafeCheck * 162/100 - : KnightSafeCheck; + kingDanger += SafeCheck[KNIGHT][more_than_one(knightChecks & safe)]; else unsafeChecks |= knightChecks; @@ -466,7 +467,7 @@ namespace { b2 = b1 & attackedBy2[Them]; b3 = attackedBy[Us][ALL_PIECES] & KingFlank[file_of(ksq)] & Camp; - int kingFlankAttack = popcount(b1) + popcount(b2); + int kingFlankAttack = popcount(b1) + popcount(b2); int kingFlankDefense = popcount(b3); kingDanger += kingAttackersCount[Them] * kingAttackersWeight[Them] @@ -727,9 +728,9 @@ namespace { } - // Evaluation::winnable() adjusts the mg and eg score components based on the - // known attacking/defending status of the players. A single value is derived - // by interpolation from the mg and eg values and returned. + // Evaluation::winnable() adjusts the midgame and endgame score components, based on + // the known attacking/defending status of the players. The final value is derived + // by interpolation from the midgame and endgame values. template Value Evaluation::winnable(Score score) const { @@ -743,8 +744,8 @@ namespace { bool almostUnwinnable = outflanking < 0 && !pawnsOnBothFlanks; - bool infiltration = rank_of(pos.square(WHITE)) > RANK_4 - || rank_of(pos.square(BLACK)) < RANK_5; + bool infiltration = rank_of(pos.square(WHITE)) > RANK_4 + || rank_of(pos.square(BLACK)) < RANK_5; // Compute the initiative bonus for the attacking side int complexity = 9 * pe->passed_count() @@ -769,11 +770,10 @@ namespace { eg += v; // Compute the scale factor for the winning side - Color strongSide = eg > VALUE_DRAW ? WHITE : BLACK; int sf = me->scale_factor(pos, strongSide); - // If scale is not already specific, scale down the endgame via general heuristics + // If scale factor is not already specific, scale down via general heuristics if (sf == SCALE_FACTOR_NORMAL) { if (pos.opposite_bishops()) @@ -784,6 +784,15 @@ namespace { else sf = 22 + 3 * pos.count(strongSide); } + else if ( pos.non_pawn_material(WHITE) == RookValueMg + && pos.non_pawn_material(BLACK) == RookValueMg + && pos.count(strongSide) - pos.count(~strongSide) <= 1 + && bool(KingSide & pos.pieces(strongSide, PAWN)) != bool(QueenSide & pos.pieces(strongSide, PAWN)) + && (attackedBy[~strongSide][KING] & pos.pieces(~strongSide, PAWN))) + sf = 36; + else if (pos.count() == 1) + sf = 37 + 3 * (pos.count(WHITE) == 1 ? pos.count(BLACK) + pos.count(BLACK) + : pos.count(WHITE) + pos.count(WHITE)); else sf = std::min(sf, 36 + 7 * pos.count(strongSide)); } diff --git a/src/movegen.cpp b/src/movegen.cpp index 17203a95..4ff12fc6 100644 --- a/src/movegen.cpp +++ b/src/movegen.cpp @@ -29,22 +29,20 @@ namespace { ExtMove* make_promotions(ExtMove* moveList, Square to, Square ksq) { if (Type == CAPTURES || Type == EVASIONS || Type == NON_EVASIONS) + { *moveList++ = make(to - D, to, QUEEN); + if (attacks_bb(to) & ksq) + *moveList++ = make(to - D, to, KNIGHT); + } if (Type == QUIETS || Type == EVASIONS || Type == NON_EVASIONS) { *moveList++ = make(to - D, to, ROOK); *moveList++ = make(to - D, to, BISHOP); - *moveList++ = make(to - D, to, KNIGHT); + if (!(attacks_bb(to) & ksq)) + *moveList++ = make(to - D, to, KNIGHT); } - // Knight promotion is the only promotion that can give a direct check - // that's not already included in the queen promotion. - if (Type == QUIET_CHECKS && (attacks_bb(to) & ksq)) - *moveList++ = make(to - D, to, KNIGHT); - else - (void)ksq; // Silence a warning under MSVC - return moveList; } @@ -263,8 +261,8 @@ namespace { } // namespace -/// Generates all pseudo-legal captures and queen promotions -/// Generates all pseudo-legal non-captures and underpromotions +/// Generates all pseudo-legal captures plus queen and checking knight promotions +/// Generates all pseudo-legal non-captures and underpromotions(except checking knight) /// Generates all pseudo-legal captures and non-captures /// /// Returns a pointer to the end of the move list. @@ -287,8 +285,8 @@ template ExtMove* generate(const Position&, ExtMove*); template ExtMove* generate(const Position&, ExtMove*); -/// generate generates all pseudo-legal non-captures and knight -/// underpromotions that give check. Returns a pointer to the end of the move list. +/// generate generates all pseudo-legal non-captures. +/// Returns a pointer to the end of the move list. template<> ExtMove* generate(const Position& pos, ExtMove* moveList) { diff --git a/src/pawns.cpp b/src/pawns.cpp index d741b2ef..7f8d451a 100644 --- a/src/pawns.cpp +++ b/src/pawns.cpp @@ -38,7 +38,12 @@ namespace { constexpr Score WeakLever = S( 0, 56); constexpr Score WeakUnopposed = S(13, 27); - constexpr Score BlockedStorm[RANK_NB] = {S( 0, 0), S( 0, 0), S( 76, 78), S(-10, 15), S(-7, 10), S(-4, 6), S(-1, 2)}; + // Bonus for blocked pawns at 5th or 6th rank + constexpr Score BlockedPawn[2] = { S(-11, -4), S(-3, 4) }; + + constexpr Score BlockedStorm[RANK_NB] = { + S(0, 0), S(0, 0), S(76, 78), S(-10, 15), S(-7, 10), S(-4, 6), S(-1, 2) + }; // Connected pawn bonus constexpr int Connected[RANK_NB] = { 0, 7, 8, 12, 29, 48, 86 }; @@ -143,7 +148,7 @@ namespace { // Score this pawn if (support | phalanx) { - int v = Connected[r] * (4 + 2 * bool(phalanx) - 2 * bool(opposed) - bool(blocked)) / 2 + int v = Connected[r] * (2 + bool(phalanx) - bool(opposed)) + 21 * popcount(support); score += make_score(v, v * (r - 2) / 4); @@ -167,6 +172,9 @@ namespace { if (!support) score -= Doubled * doubled + WeakLever * more_than_one(lever); + + if (blocked && r > RANK_4) + score += BlockedPawn[r-4]; } return score; diff --git a/src/position.cpp b/src/position.cpp index 917d1646..90677337 100644 --- a/src/position.cpp +++ b/src/position.cpp @@ -119,15 +119,7 @@ void Position::init() { Zobrist::enpassant[f] = rng.rand(); for (int cr = NO_CASTLING; cr <= ANY_CASTLING; ++cr) - { - Zobrist::castling[cr] = 0; - Bitboard b = cr; - while (b) - { - Key k = Zobrist::castling[1ULL << pop_lsb(&b)]; - Zobrist::castling[cr] ^= k ? k : rng.rand(); - } - } + Zobrist::castling[cr] = rng.rand(); Zobrist::side = rng.rand(); Zobrist::noPawns = rng.rand(); @@ -186,9 +178,9 @@ Position& Position::set(const string& fenStr, bool isChess960, StateInfo* si, Th 4) En passant target square (in algebraic notation). If there's no en passant target square, this is "-". If a pawn has just made a 2-square move, this - is the position "behind" the pawn. This is recorded only if there is a pawn - in position to make an en passant capture, and if there really is a pawn - that might have advanced two squares. + is the position "behind" the pawn. Following X-FEN standard, this is recorded only + if there is a pawn in position to make an en passant capture, and if there really + is a pawn that might have advanced two squares. 5) Halfmove clock. This is the number of halfmoves since the last pawn advance or capture. This is used to determine if a draw can be claimed under the @@ -278,17 +270,25 @@ Position& Position::set(const string& fenStr, bool isChess960, StateInfo* si, Th set_castling_right(c, rsq); } - // 4. En passant square. Ignore if no pawn capture is possible + // 4. En passant square. + // Ignore if square is invalid or not on side to move relative rank 6. + bool enpassant = false; + if ( ((ss >> col) && (col >= 'a' && col <= 'h')) - && ((ss >> row) && (row == '3' || row == '6'))) + && ((ss >> row) && (row == (sideToMove == WHITE ? '6' : '3')))) { st->epSquare = make_square(File(col - 'a'), Rank(row - '1')); - if ( !(attackers_to(st->epSquare) & pieces(sideToMove, PAWN)) - || !(pieces(~sideToMove, PAWN) & (st->epSquare + pawn_push(~sideToMove)))) - st->epSquare = SQ_NONE; + // En passant square will be considered only if + // a) side to move have a pawn threatening epSquare + // b) there is an enemy pawn in front of epSquare + // c) there is no piece on epSquare or behind epSquare + enpassant = pawn_attacks_bb(~sideToMove, st->epSquare) & pieces(sideToMove, PAWN) + && (pieces(~sideToMove, PAWN) & (st->epSquare + pawn_push(~sideToMove))) + && !(pieces() & (st->epSquare | (st->epSquare + pawn_push(sideToMove)))); } - else + + if (!enpassant) st->epSquare = SQ_NONE; // 5-6. Halfmove clock and fullmove number @@ -851,9 +851,9 @@ void Position::do_move(Move m, StateInfo& newSt, bool givesCheck) { // Update castling rights if needed if (st->castlingRights && (castlingRightsMask[from] | castlingRightsMask[to])) { - int cr = castlingRightsMask[from] | castlingRightsMask[to]; - k ^= Zobrist::castling[st->castlingRights & cr]; - st->castlingRights &= ~cr; + k ^= Zobrist::castling[st->castlingRights]; + st->castlingRights &= ~(castlingRightsMask[from] | castlingRightsMask[to]); + k ^= Zobrist::castling[st->castlingRights]; } // Move the piece. The tricky Chess960 castling is handled earlier diff --git a/src/psqt.cpp b/src/psqt.cpp index c5da9785..5e8dd2c7 100644 --- a/src/psqt.cpp +++ b/src/psqt.cpp @@ -92,7 +92,7 @@ constexpr Score PBonus[RANK_NB][FILE_NB] = { S( 3,-10), S( 3, -6), S( 10, 10), S( 19, 0), S( 16, 14), S( 19, 7), S( 7, -5), S( -5,-19) }, { S( -9,-10), S(-15,-10), S( 11,-10), S( 15, 4), S( 32, 4), S( 22, 3), S( 5, -6), S(-22, -4) }, { S( -4, 6), S(-23, -2), S( 6, -8), S( 20, -4), S( 40,-13), S( 17,-12), S( 4,-10), S( -8, -9) }, - { S( 13, 9), S( 0, 4), S(-13, 3), S( 1,-12), S( 11,-12), S( -2, -6), S(-13, 13), S( 5, 8) }, + { S( 13, 10), S( 0, 5), S(-13, 4), S( 1, -5), S( 11, -5), S( -2, -5), S(-13, 14), S( 5, 9) }, { S( 5, 28), S(-12, 20), S( -7, 21), S( 22, 28), S( -8, 30), S( -5, 7), S(-15, 6), S( -8, 13) }, { S( -7, 0), S( 7,-11), S( -3, 12), S(-13, 21), S( 5, 25), S(-16, 19), S( 10, 4), S( -8, 7) } }; diff --git a/src/search.cpp b/src/search.cpp index 5990905f..3ccc1d89 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -263,10 +263,10 @@ void MainThread::search() { Thread* bestThread = this; - if (int(Options["MultiPV"]) == 1 && - !Limits.depth && - !(Skill(Options["Skill Level"]).enabled() || int(Options["UCI_LimitStrength"])) && - rootMoves[0].pv[0] != MOVE_NONE) + if ( int(Options["MultiPV"]) == 1 + && !Limits.depth + && !(Skill(Options["Skill Level"]).enabled() || int(Options["UCI_LimitStrength"])) + && rootMoves[0].pv[0] != MOVE_NONE) bestThread = Threads.get_best_thread(); bestPreviousScore = bestThread->rootMoves[0].score; @@ -596,7 +596,7 @@ namespace { Key posKey; Move ttMove, move, excludedMove, bestMove; Depth extension, newDepth; - Value bestValue, value, ttValue, eval, maxValue; + Value bestValue, value, ttValue, eval, maxValue, probcutBeta; bool ttHit, ttPv, formerPv, givesCheck, improving, didLMR, priorCapture; bool captureOrPromotion, doFullDepthSearch, moveCountPruning, ttCapture, singularQuietLMR; @@ -662,7 +662,7 @@ namespace { // search to overwrite a previous full search TT value, so we use a different // position key in case of an excluded move. excludedMove = ss->excludedMove; - posKey = pos.key() ^ (Key(excludedMove) << 48); // Isn't a very good hash + posKey = excludedMove == MOVE_NONE ? pos.key() : pos.key() ^ make_key(excludedMove); tte = TT.probe(posKey, ttHit); ttValue = ttHit ? value_from_tt(tte->value(), ss->ply, pos.rule50_count()) : VALUE_NONE; ttMove = rootNode ? thisThread->rootMoves[thisThread->pvIdx].pv[0] @@ -670,7 +670,11 @@ namespace { ttPv = PvNode || (ttHit && tte->is_pv()); formerPv = ttPv && !PvNode; - if (ttPv && depth > 12 && ss->ply - 1 < MAX_LPH && !priorCapture && is_ok((ss-1)->currentMove)) + if ( ttPv + && depth > 12 + && ss->ply - 1 < MAX_LPH + && !priorCapture + && is_ok((ss-1)->currentMove)) thisThread->lowPlyHistory[ss->ply - 1][from_to((ss-1)->currentMove)] << stat_bonus(depth - 5); // thisThread->ttHitAverage can be used to approximate the running average of ttHit @@ -867,23 +871,33 @@ namespace { } } + probcutBeta = beta + 176 - 49 * improving; + // Step 10. ProbCut (~10 Elo) // If we have a good enough capture and a reduced search returns a value // much above beta, we can (almost) safely prune the previous move. if ( !PvNode && depth > 4 - && abs(beta) < VALUE_TB_WIN_IN_MAX_PLY) + && abs(beta) < VALUE_TB_WIN_IN_MAX_PLY + && !( ttHit + && tte->depth() >= depth - 3 + && ttValue != VALUE_NONE + && ttValue < probcutBeta)) { - Value raisedBeta = beta + 176 - 49 * improving; - assert(raisedBeta < VALUE_INFINITE); - MovePicker mp(pos, ttMove, raisedBeta - ss->staticEval, &captureHistory); + if ( ttHit + && tte->depth() >= depth - 3 + && ttValue != VALUE_NONE + && ttValue >= probcutBeta + && ttMove + && pos.capture_or_promotion(ttMove)) + return probcutBeta; + + assert(probcutBeta < VALUE_INFINITE); + MovePicker mp(pos, ttMove, probcutBeta - ss->staticEval, &captureHistory); int probCutCount = 0; while ( (move = mp.next_move()) != MOVE_NONE - && probCutCount < 2 + 2 * cutNode - && !( move == ttMove - && tte->depth() >= depth - 4 - && ttValue < raisedBeta)) + && probCutCount < 2 + 2 * cutNode) if (move != excludedMove && pos.legal(move)) { assert(pos.capture_or_promotion(move)); @@ -901,16 +915,21 @@ namespace { pos.do_move(move, st); // Perform a preliminary qsearch to verify that the move holds - value = -qsearch(pos, ss+1, -raisedBeta, -raisedBeta+1); + value = -qsearch(pos, ss+1, -probcutBeta, -probcutBeta+1); // If the qsearch held, perform the regular search - if (value >= raisedBeta) - value = -search(pos, ss+1, -raisedBeta, -raisedBeta+1, depth - 4, !cutNode); + if (value >= probcutBeta) + value = -search(pos, ss+1, -probcutBeta, -probcutBeta+1, depth - 4, !cutNode); pos.undo_move(move); - if (value >= raisedBeta) + if (value >= probcutBeta) + { + tte->save(posKey, value_to_tt(value, ss->ply), ttPv, + BOUND_LOWER, + depth - 3, move, ss->staticEval); return value; + } } } @@ -1486,8 +1505,8 @@ moves_loop: // When in check, search starts from here // Initialize a MovePicker object for the current position, and prepare // to search the moves. Because the depth is <= 0 here, only captures, - // queen promotions and checks (only if depth >= DEPTH_QS_CHECKS) will - // be generated. + // queen and checking knight promotions, and other checks(only if depth >= DEPTH_QS_CHECKS) + // will be generated. MovePicker mp(pos, ttMove, depth, &thisThread->mainHistory, &thisThread->captureHistory, contHist, diff --git a/src/types.h b/src/types.h index 33a35483..773d9247 100644 --- a/src/types.h +++ b/src/types.h @@ -501,6 +501,11 @@ inline PieceNumber& operator--(PieceNumber& d) { return d = PieceNumber(int8_t(d constexpr bool is_ok(PieceNumber pn) { return pn < PIECE_NUMBER_NB; } #endif // defined(EVAL_NNUE) || defined(EVAL_LEARN) +/// Based on a congruential pseudo random number generator +constexpr Key make_key(uint64_t seed) { + return seed * 6364136223846793005ULL + 1442695040888963407ULL; +} + #endif // #ifndef TYPES_H_INCLUDED #include "tune.h" // Global visibility to tuning setup