X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovepick.cpp;h=694b9222fe573945c826e627865e6b4d5565f58c;hp=65155a73f7936a308b13d099cb9071e704ce4298;hb=HEAD;hpb=a2038c1a011552c3d56d3b318780f7f5eadaf05d diff --git a/src/movepick.cpp b/src/movepick.cpp index 65155a73..0267a8e2 100644 --- a/src/movepick.cpp +++ b/src/movepick.cpp @@ -16,281 +16,351 @@ along with this program. If not, see . */ +#include "movepick.h" + +#include #include +#include +#include #include "bitboard.h" -#include "movepick.h" +#include "position.h" namespace Stockfish { namespace { - enum Stages { - MAIN_TT, CAPTURE_INIT, GOOD_CAPTURE, REFUTATION, QUIET_INIT, QUIET, BAD_CAPTURE, - EVASION_TT, EVASION_INIT, EVASION, - PROBCUT_TT, PROBCUT_INIT, PROBCUT, - QSEARCH_TT, QCAPTURE_INIT, QCAPTURE, QCHECK_INIT, QCHECK - }; - - // partial_insertion_sort() sorts moves in descending order up to and including - // a given limit. The order of moves smaller than the limit is left unspecified. - void partial_insertion_sort(ExtMove* begin, ExtMove* end, int limit) { +enum Stages { + // generate main search moves + MAIN_TT, + CAPTURE_INIT, + GOOD_CAPTURE, + REFUTATION, + QUIET_INIT, + QUIET, + BAD_CAPTURE, + + // generate evasion moves + EVASION_TT, + EVASION_INIT, + EVASION, + + // generate probcut moves + PROBCUT_TT, + PROBCUT_INIT, + PROBCUT, + + // generate qsearch moves + QSEARCH_TT, + QCAPTURE_INIT, + QCAPTURE, + QCHECK_INIT, + QCHECK +}; + +// Sort moves in descending order up to and including +// a given limit. The order of moves smaller than the limit is left unspecified. +void partial_insertion_sort(ExtMove* begin, ExtMove* end, int limit) { for (ExtMove *sortedEnd = begin, *p = begin + 1; p < end; ++p) if (p->value >= limit) { ExtMove tmp = *p, *q; - *p = *++sortedEnd; + *p = *++sortedEnd; for (q = sortedEnd; q != begin && *(q - 1) < tmp; --q) *q = *(q - 1); *q = tmp; } - } - -} // namespace - - -/// Constructors of the MovePicker class. As arguments we pass information -/// to help it to return the (presumably) good moves first, to decide which -/// moves to return (in the quiescence search, for instance, we only want to -/// search captures, promotions, and some checks) and how important good move -/// ordering is at the current node. - -/// MovePicker constructor for the main search -MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHistory* mh, - const CapturePieceToHistory* cph, - const PieceToHistory** ch, - Move cm, - const Move* killers) - : pos(p), mainHistory(mh), captureHistory(cph), continuationHistory(ch), - ttMove(ttm), refutations{{killers[0], 0}, {killers[1], 0}, {cm, 0}}, depth(d) -{ - assert(d > 0); - - stage = (pos.checkers() ? EVASION_TT : MAIN_TT) + - !(ttm && pos.pseudo_legal(ttm)); - threatenedPieces = 0; } -/// MovePicker constructor for quiescence search -MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHistory* mh, - const CapturePieceToHistory* cph, - const PieceToHistory** ch, - Square rs) - : pos(p), mainHistory(mh), captureHistory(cph), continuationHistory(ch), ttMove(ttm), recaptureSquare(rs), depth(d) -{ - assert(d <= 0); - - stage = (pos.checkers() ? EVASION_TT : QSEARCH_TT) + - !( ttm - && pos.pseudo_legal(ttm)); +} // namespace + + +// Constructors of the MovePicker class. As arguments, we pass information +// to help it return the (presumably) good moves first, to decide which +// moves to return (in the quiescence search, for instance, we only want to +// search captures, promotions, and some checks) and how important a good +// move ordering is at the current node. + +// MovePicker constructor for the main search +MovePicker::MovePicker(const Position& p, + Move ttm, + Depth d, + const ButterflyHistory* mh, + const CapturePieceToHistory* cph, + const PieceToHistory** ch, + const PawnHistory* ph, + Move cm, + const Move* killers) : + pos(p), + mainHistory(mh), + captureHistory(cph), + continuationHistory(ch), + pawnHistory(ph), + ttMove(ttm), + refutations{{killers[0], 0}, {killers[1], 0}, {cm, 0}}, + depth(d) { + assert(d > 0); + + stage = (pos.checkers() ? EVASION_TT : MAIN_TT) + !(ttm && pos.pseudo_legal(ttm)); } -/// MovePicker constructor for ProbCut: we generate captures with SEE greater -/// than or equal to the given threshold. -MovePicker::MovePicker(const Position& p, Move ttm, Value th, const CapturePieceToHistory* cph) - : pos(p), captureHistory(cph), ttMove(ttm), threshold(th) -{ - assert(!pos.checkers()); +// Constructor for quiescence search +MovePicker::MovePicker(const Position& p, + Move ttm, + Depth d, + const ButterflyHistory* mh, + const CapturePieceToHistory* cph, + const PieceToHistory** ch, + const PawnHistory* ph) : + pos(p), + mainHistory(mh), + captureHistory(cph), + continuationHistory(ch), + pawnHistory(ph), + ttMove(ttm), + depth(d) { + assert(d <= 0); + + stage = (pos.checkers() ? EVASION_TT : QSEARCH_TT) + !(ttm && pos.pseudo_legal(ttm)); +} - stage = PROBCUT_TT + !(ttm && pos.capture(ttm) - && pos.pseudo_legal(ttm) - && pos.see_ge(ttm, threshold)); +// Constructor for ProbCut: we generate captures with SEE greater +// than or equal to the given threshold. +MovePicker::MovePicker(const Position& p, Move ttm, Value th, const CapturePieceToHistory* cph) : + pos(p), + captureHistory(cph), + ttMove(ttm), + threshold(th) { + assert(!pos.checkers()); + + stage = PROBCUT_TT + + !(ttm && pos.capture_stage(ttm) && pos.pseudo_legal(ttm) && pos.see_ge(ttm, threshold)); } -/// MovePicker::score() assigns a numerical value to each move in a list, used -/// for sorting. Captures are ordered by Most Valuable Victim (MVV), preferring -/// captures with a good history. Quiets moves are ordered using the history tables. +// Assigns a numerical value to each move in a list, used +// for sorting. Captures are ordered by Most Valuable Victim (MVV), preferring +// captures with a good history. Quiets moves are ordered using the history tables. template void MovePicker::score() { - static_assert(Type == CAPTURES || Type == QUIETS || Type == EVASIONS, "Wrong type"); - - [[maybe_unused]] Bitboard threatenedByPawn, threatenedByMinor, threatenedByRook; - if constexpr (Type == QUIETS) - { - Color us = pos.side_to_move(); - - threatenedByPawn = pos.attacks_by(~us); - threatenedByMinor = pos.attacks_by(~us) | pos.attacks_by(~us) | threatenedByPawn; - threatenedByRook = pos.attacks_by(~us) | threatenedByMinor; - - // Pieces threatened by pieces of lesser material value - threatenedPieces = (pos.pieces(us, QUEEN) & threatenedByRook) - | (pos.pieces(us, ROOK) & threatenedByMinor) - | (pos.pieces(us, KNIGHT, BISHOP) & threatenedByPawn); - } - - for (auto& m : *this) - if constexpr (Type == CAPTURES) - m.value = (7 * int(PieceValue[MG][pos.piece_on(to_sq(m))]) - + (*captureHistory)[pos.moved_piece(m)][to_sq(m)][type_of(pos.piece_on(to_sq(m)))]) / 16; - - else if constexpr (Type == QUIETS) - m.value = 2 * (*mainHistory)[pos.side_to_move()][from_to(m)] - + 2 * (*continuationHistory[0])[pos.moved_piece(m)][to_sq(m)] - + (*continuationHistory[1])[pos.moved_piece(m)][to_sq(m)] - + (*continuationHistory[3])[pos.moved_piece(m)][to_sq(m)] - + (*continuationHistory[5])[pos.moved_piece(m)][to_sq(m)] - + (threatenedPieces & from_sq(m) ? - (type_of(pos.moved_piece(m)) == QUEEN && !(to_sq(m) & threatenedByRook) ? 50000 - : type_of(pos.moved_piece(m)) == ROOK && !(to_sq(m) & threatenedByMinor) ? 25000 - : !(to_sq(m) & threatenedByPawn) ? 15000 - : 0) - : 0) - + bool(pos.check_squares(type_of(pos.moved_piece(m))) & to_sq(m)) * 16384; - else // Type == EVASIONS - { - if (pos.capture(m)) - m.value = PieceValue[MG][pos.piece_on(to_sq(m))] - - Value(type_of(pos.moved_piece(m))) - + (1 << 28); - else - m.value = (*mainHistory)[pos.side_to_move()][from_to(m)] - + (*continuationHistory[0])[pos.moved_piece(m)][to_sq(m)]; - } + static_assert(Type == CAPTURES || Type == QUIETS || Type == EVASIONS, "Wrong type"); + + [[maybe_unused]] Bitboard threatenedByPawn, threatenedByMinor, threatenedByRook, + threatenedPieces; + if constexpr (Type == QUIETS) + { + Color us = pos.side_to_move(); + + threatenedByPawn = pos.attacks_by(~us); + threatenedByMinor = + pos.attacks_by(~us) | pos.attacks_by(~us) | threatenedByPawn; + threatenedByRook = pos.attacks_by(~us) | threatenedByMinor; + + // Pieces threatened by pieces of lesser material value + threatenedPieces = (pos.pieces(us, QUEEN) & threatenedByRook) + | (pos.pieces(us, ROOK) & threatenedByMinor) + | (pos.pieces(us, KNIGHT, BISHOP) & threatenedByPawn); + } + + for (auto& m : *this) + if constexpr (Type == CAPTURES) + m.value = + (7 * int(PieceValue[pos.piece_on(to_sq(m))]) + + (*captureHistory)[pos.moved_piece(m)][to_sq(m)][type_of(pos.piece_on(to_sq(m)))]) + / 16; + + else if constexpr (Type == QUIETS) + { + Piece pc = pos.moved_piece(m); + PieceType pt = type_of(pos.moved_piece(m)); + Square from = from_sq(m); + Square to = to_sq(m); + + // histories + m.value = 2 * (*mainHistory)[pos.side_to_move()][from_to(m)]; + m.value += 2 * (*pawnHistory)[pawn_structure(pos)][pc][to]; + m.value += 2 * (*continuationHistory[0])[pc][to]; + m.value += (*continuationHistory[1])[pc][to]; + m.value += (*continuationHistory[2])[pc][to] / 4; + m.value += (*continuationHistory[3])[pc][to]; + m.value += (*continuationHistory[5])[pc][to]; + + // bonus for checks + m.value += bool(pos.check_squares(pt) & to) * 16384; + + // bonus for escaping from capture + m.value += threatenedPieces & from ? (pt == QUEEN && !(to & threatenedByRook) ? 50000 + : pt == ROOK && !(to & threatenedByMinor) ? 25000 + : !(to & threatenedByPawn) ? 15000 + : 0) + : 0; + + // malus for putting piece en prise + m.value -= !(threatenedPieces & from) + ? (pt == QUEEN ? bool(to & threatenedByRook) * 50000 + + bool(to & threatenedByMinor) * 10000 + + bool(to & threatenedByPawn) * 20000 + : pt == ROOK ? bool(to & threatenedByMinor) * 25000 + + bool(to & threatenedByPawn) * 10000 + : pt != PAWN ? bool(to & threatenedByPawn) * 15000 + : 0) + : 0; + } + + else // Type == EVASIONS + { + if (pos.capture_stage(m)) + m.value = PieceValue[pos.piece_on(to_sq(m))] - Value(type_of(pos.moved_piece(m))) + + (1 << 28); + else + m.value = (*mainHistory)[pos.side_to_move()][from_to(m)] + + (*continuationHistory[0])[pos.moved_piece(m)][to_sq(m)] + + (*pawnHistory)[pawn_structure(pos)][pos.moved_piece(m)][to_sq(m)]; + } } -/// MovePicker::select() returns the next move satisfying a predicate function. -/// It never returns the TT move. +// Returns the next move satisfying a predicate function. +// It never returns the TT move. template Move MovePicker::select(Pred filter) { - while (cur < endMoves) - { - if constexpr (T == Best) - std::swap(*cur, *std::max_element(cur, endMoves)); + while (cur < endMoves) + { + if constexpr (T == Best) + std::swap(*cur, *std::max_element(cur, endMoves)); - if (*cur != ttMove && filter()) - return *cur++; + if (*cur != ttMove && filter()) + return *cur++; - cur++; - } - return MOVE_NONE; + cur++; + } + return MOVE_NONE; } -/// MovePicker::next_move() is the most important method of the MovePicker class. It -/// returns a new pseudo-legal move every time it is called until there are no more -/// moves left, picking the move with the highest score from a list of generated moves. +// Most important method of the MovePicker class. It +// returns a new pseudo-legal move every time it is called until there are no more +// moves left, picking the move with the highest score from a list of generated moves. Move MovePicker::next_move(bool skipQuiets) { top: - switch (stage) { - - case MAIN_TT: - case EVASION_TT: - case QSEARCH_TT: - case PROBCUT_TT: - ++stage; - return ttMove; - - case CAPTURE_INIT: - case PROBCUT_INIT: - case QCAPTURE_INIT: - cur = endBadCaptures = moves; - endMoves = generate(pos, cur); - - score(); - partial_insertion_sort(cur, endMoves, std::numeric_limits::min()); - ++stage; - goto top; - - case GOOD_CAPTURE: - if (select([&](){ - return pos.see_ge(*cur, Value(-cur->value)) ? - // Move losing capture to endBadCaptures to be tried later - true : (*endBadCaptures++ = *cur, false); })) - return *(cur - 1); - - // Prepare the pointers to loop over the refutations array - cur = std::begin(refutations); - endMoves = std::end(refutations); - - // If the countermove is the same as a killer, skip it - if ( refutations[0].move == refutations[2].move - || refutations[1].move == refutations[2].move) - --endMoves; - - ++stage; - [[fallthrough]]; - - case REFUTATION: - if (select([&](){ return *cur != MOVE_NONE - && !pos.capture(*cur) - && pos.pseudo_legal(*cur); })) - return *(cur - 1); - ++stage; - [[fallthrough]]; - - case QUIET_INIT: - if (!skipQuiets) - { - cur = endBadCaptures; - endMoves = generate(pos, cur); - - score(); - partial_insertion_sort(cur, endMoves, -3000 * depth); - } - - ++stage; - [[fallthrough]]; - - case QUIET: - if ( !skipQuiets - && select([&](){return *cur != refutations[0].move - && *cur != refutations[1].move - && *cur != refutations[2].move;})) - return *(cur - 1); - - // Prepare the pointers to loop over the bad captures - cur = moves; - endMoves = endBadCaptures; - - ++stage; - [[fallthrough]]; - - case BAD_CAPTURE: - return select([](){ return true; }); - - case EVASION_INIT: - cur = moves; - endMoves = generate(pos, cur); - - score(); - ++stage; - [[fallthrough]]; - - case EVASION: - return select([](){ return true; }); - - case PROBCUT: - return select([&](){ return pos.see_ge(*cur, threshold); }); - - case QCAPTURE: - if (select([&](){ return depth > DEPTH_QS_RECAPTURES - || to_sq(*cur) == recaptureSquare; })) - return *(cur - 1); - - // If we did not find any move and we do not try checks, we have finished - if (depth != DEPTH_QS_CHECKS) - return MOVE_NONE; - - ++stage; - [[fallthrough]]; - - case QCHECK_INIT: - cur = moves; - endMoves = generate(pos, cur); - - ++stage; - [[fallthrough]]; - - case QCHECK: - return select([](){ return true; }); - } - - assert(false); - return MOVE_NONE; // Silence warning + switch (stage) + { + + case MAIN_TT : + case EVASION_TT : + case QSEARCH_TT : + case PROBCUT_TT : + ++stage; + return ttMove; + + case CAPTURE_INIT : + case PROBCUT_INIT : + case QCAPTURE_INIT : + cur = endBadCaptures = moves; + endMoves = generate(pos, cur); + + score(); + partial_insertion_sort(cur, endMoves, std::numeric_limits::min()); + ++stage; + goto top; + + case GOOD_CAPTURE : + if (select([&]() { + // Move losing capture to endBadCaptures to be tried later + return pos.see_ge(*cur, Value(-cur->value)) ? true + : (*endBadCaptures++ = *cur, false); + })) + return *(cur - 1); + + // Prepare the pointers to loop over the refutations array + cur = std::begin(refutations); + endMoves = std::end(refutations); + + // If the countermove is the same as a killer, skip it + if (refutations[0].move == refutations[2].move + || refutations[1].move == refutations[2].move) + --endMoves; + + ++stage; + [[fallthrough]]; + + case REFUTATION : + if (select([&]() { + return *cur != MOVE_NONE && !pos.capture_stage(*cur) && pos.pseudo_legal(*cur); + })) + return *(cur - 1); + ++stage; + [[fallthrough]]; + + case QUIET_INIT : + if (!skipQuiets) + { + cur = endBadCaptures; + endMoves = generate(pos, cur); + + score(); + partial_insertion_sort(cur, endMoves, -1960 - 3130 * depth); + } + + ++stage; + [[fallthrough]]; + + case QUIET : + if (!skipQuiets && select([&]() { + return *cur != refutations[0].move && *cur != refutations[1].move + && *cur != refutations[2].move; + })) + return *(cur - 1); + + // Prepare the pointers to loop over the bad captures + cur = moves; + endMoves = endBadCaptures; + + ++stage; + [[fallthrough]]; + + case BAD_CAPTURE : + return select([]() { return true; }); + + case EVASION_INIT : + cur = moves; + endMoves = generate(pos, cur); + + score(); + ++stage; + [[fallthrough]]; + + case EVASION : + return select([]() { return true; }); + + case PROBCUT : + return select([&]() { return pos.see_ge(*cur, threshold); }); + + case QCAPTURE : + if (select([]() { return true; })) + return *(cur - 1); + + // If we did not find any move and we do not try checks, we have finished + if (depth != DEPTH_QS_CHECKS) + return MOVE_NONE; + + ++stage; + [[fallthrough]]; + + case QCHECK_INIT : + cur = moves; + endMoves = generate(pos, cur); + + ++stage; + [[fallthrough]]; + + case QCHECK : + return select([]() { return true; }); + } + + assert(false); + return MOVE_NONE; // Silence warning } -} // namespace Stockfish +} // namespace Stockfish