X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovepick.cpp;h=8f49b1dd434cf66ae1ccce0475d02dd3c45814df;hp=c0809f2805f39c211bb9aba6f70cf7aa051dbf55;hb=12e79be91039796299187ba1b2f1559552642ea4;hpb=cad300cfab869a4e8dcc6b286f9b2e60d2827bed diff --git a/src/movepick.cpp b/src/movepick.cpp index c0809f28..8f49b1dd 100644 --- a/src/movepick.cpp +++ b/src/movepick.cpp @@ -25,12 +25,15 @@ namespace { enum Stages { - MAIN_SEARCH, CAPTURES_INIT, GOOD_CAPTURES, KILLER0, KILLER1, COUNTERMOVE, QUIET_INIT, QUIET, BAD_CAPTURES, - EVASION, EVASIONS_INIT, ALL_EVASIONS, - PROBCUT, PROBCUT_CAPTURES_INIT, PROBCUT_CAPTURES, - QSEARCH, QCAPTURES_INIT, QCAPTURES, QCHECKS + 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 }; + // Helper filter used with select() + const auto Any = [](){ return true; }; + // 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) { @@ -46,15 +49,6 @@ namespace { } } - // pick_best() finds the best move in the range (begin, end) and moves it to - // the front. It's faster than sorting all the moves in advance when there - // are few moves, e.g., the possible captures. - Move pick_best(ExtMove* begin, ExtMove* end) { - - std::swap(*begin, *std::max_element(begin, end)); - return *begin; - } - } // namespace @@ -66,38 +60,39 @@ namespace { /// 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, Move* killers_p) - : pos(p), mainHistory(mh), captureHistory(cph), contHistory(ch), countermove(cm), - killers{killers_p[0], killers_p[1]}, depth(d){ + const CapturePieceToHistory* cph, const PieceToHistory** ch, Move cm, Move* killers) + : pos(p), mainHistory(mh), captureHistory(cph), continuationHistory(ch), + refutations{{killers[0], 0}, {killers[1], 0}, {cm, 0}}, depth(d) { assert(d > DEPTH_ZERO); - stage = pos.checkers() ? EVASION : MAIN_SEARCH; + stage = pos.checkers() ? EVASION_TT : MAIN_TT; ttMove = ttm && pos.pseudo_legal(ttm) ? ttm : MOVE_NONE; stage += (ttMove == MOVE_NONE); } /// MovePicker constructor for quiescence search -MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHistory* mh, const CapturePieceToHistory* cph, Square s) - : pos(p), mainHistory(mh), captureHistory(cph), recaptureSquare(s), depth(d) { +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), recaptureSquare(rs), depth(d) { assert(d <= DEPTH_ZERO); - stage = pos.checkers() ? EVASION : QSEARCH; + stage = pos.checkers() ? EVASION_TT : QSEARCH_TT; ttMove = ttm && pos.pseudo_legal(ttm) && (depth > DEPTH_QS_RECAPTURES || to_sq(ttm) == recaptureSquare) ? ttm : MOVE_NONE; stage += (ttMove == MOVE_NONE); } -/// MovePicker constructor for ProbCut: we generate captures with SEE higher +/// 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), threshold(th) { assert(!pos.checkers()); - stage = PROBCUT; + stage = PROBCUT_TT; ttMove = ttm && pos.pseudo_legal(ttm) && pos.capture(ttm) @@ -105,9 +100,9 @@ MovePicker::MovePicker(const Position& p, Move ttm, Value th, const CapturePiece stage += (ttMove == MOVE_NONE); } -/// 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 are ordered using the histories. +/// 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 histories. template void MovePicker::score() { @@ -116,13 +111,13 @@ void MovePicker::score() { for (auto& m : *this) if (Type == CAPTURES) m.value = PieceValue[MG][pos.piece_on(to_sq(m))] - + (*captureHistory)[pos.moved_piece(m)][to_sq(m)][type_of(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 (Type == QUIETS) m.value = (*mainHistory)[pos.side_to_move()][from_to(m)] - + (*contHistory[0])[pos.moved_piece(m)][to_sq(m)] - + (*contHistory[1])[pos.moved_piece(m)][to_sq(m)] - + (*contHistory[3])[pos.moved_piece(m)][to_sq(m)]; + + (*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)]; else // Type == EVASIONS { @@ -130,158 +125,145 @@ void MovePicker::score() { m.value = PieceValue[MG][pos.piece_on(to_sq(m))] - Value(type_of(pos.moved_piece(m))); else - m.value = (*mainHistory)[pos.side_to_move()][from_to(m)] - (1 << 28); + m.value = (*mainHistory)[pos.side_to_move()][from_to(m)] + + (*continuationHistory[0])[pos.moved_piece(m)][to_sq(m)] + - (1 << 28); } } -/// 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. It picks the move with the biggest value from a list of generated moves -/// taking care not to return the ttMove if it has already been searched. +/// MovePicker::select() returns the next move satisfying a predicate function. +/// It never returns the TT move. +template +Move MovePicker::select(Pred filter) { -Move MovePicker::next_move(bool skipQuiets) { + while (cur < endMoves) + { + if (T == Best) + std::swap(*cur, *std::max_element(cur, endMoves)); - Move move; + move = *cur++; + + if (move != ttMove && filter()) + return move; + } + return move = 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. +Move MovePicker::next_move(bool skipQuiets) { +top: switch (stage) { - case MAIN_SEARCH: case EVASION: case QSEARCH: case PROBCUT: + case MAIN_TT: + case EVASION_TT: + case QSEARCH_TT: + case PROBCUT_TT: ++stage; return ttMove; - case CAPTURES_INIT: - case PROBCUT_CAPTURES_INIT: - case QCAPTURES_INIT: - endBadCaptures = cur = moves; + case CAPTURE_INIT: + case PROBCUT_INIT: + case QCAPTURE_INIT: + cur = endBadCaptures = moves; endMoves = generate(pos, cur); + score(); ++stage; + goto top; - // Rebranch at the top of the switch via a recursive call - return next_move(skipQuiets); + case GOOD_CAPTURE: + if (select([&](){ + return pos.see_ge(move, Value(-55 * (cur-1)->value / 1024)) ? + // Move losing capture to endBadCaptures to be tried later + true : (*endBadCaptures++ = move, false); })) + return move; - case GOOD_CAPTURES: - while (cur < endMoves) - { - move = pick_best(cur++, endMoves); - if (move != ttMove) - { - if (pos.see_ge(move, Value(-55 * (cur-1)->value / 1024))) - return move; - - // Losing capture, move it to the beginning of the array - *endBadCaptures++ = move; - } - } - ++stage; - /* fallthrough */ + // Prepare the pointers to loop over the refutations array + cur = std::begin(refutations); + endMoves = std::end(refutations); - case KILLER0: - case KILLER1: - do - { - move = killers[++stage - KILLER1]; - if ( move != MOVE_NONE - && move != ttMove - && pos.pseudo_legal(move) - && !pos.capture(move)) - return move; - } while (stage <= KILLER1); - /* fallthrough */ + // 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; - case COUNTERMOVE: ++stage; - move = countermove; - if ( move != MOVE_NONE - && move != ttMove - && move != killers[0] - && move != killers[1] - && pos.pseudo_legal(move) - && !pos.capture(move)) + /* fallthrough */ + + case REFUTATION: + if (select([&](){ return move != MOVE_NONE + && !pos.capture(move) + && pos.pseudo_legal(move); })) return move; + ++stage; /* fallthrough */ case QUIET_INIT: cur = endBadCaptures; endMoves = generate(pos, cur); + score(); partial_insertion_sort(cur, endMoves, -4000 * depth / ONE_PLY); ++stage; /* fallthrough */ case QUIET: - if (!skipQuiets) - while (cur < endMoves) - { - move = *cur++; - if ( move != ttMove - && move != killers[0] - && move != killers[1] - && move != countermove) - return move; - } + if ( !skipQuiets + && select([&](){return move != refutations[0] + && move != refutations[1] + && move != refutations[2];})) + return move; + + // Prepare the pointers to loop over the bad captures + cur = moves; + endMoves = endBadCaptures; + ++stage; - cur = moves; // Point to beginning of bad captures /* fallthrough */ - case BAD_CAPTURES: - if (cur < endBadCaptures) - return *cur++; - break; + case BAD_CAPTURE: + return select(Any); - case EVASIONS_INIT: + case EVASION_INIT: cur = moves; endMoves = generate(pos, cur); + score(); ++stage; /* fallthrough */ - case ALL_EVASIONS: - while (cur < endMoves) - { - move = pick_best(cur++, endMoves); - if (move != ttMove) - return move; - } - break; + case EVASION: + return select(Any); - case PROBCUT_CAPTURES: - while (cur < endMoves) - { - move = pick_best(cur++, endMoves); - if ( move != ttMove - && pos.see_ge(move, threshold)) - return move; - } - break; + case PROBCUT: + return select([&](){ return pos.see_ge(move, threshold); }); - case QCAPTURES: - while (cur < endMoves) - { - move = pick_best(cur++, endMoves); - if ( move != ttMove - && (depth > DEPTH_QS_RECAPTURES || to_sq(move) == recaptureSquare)) - return move; - } - if (depth <= DEPTH_QS_NO_CHECKS) - break; + case QCAPTURE: + if (select([&](){ return depth > DEPTH_QS_RECAPTURES + || to_sq(move) == recaptureSquare; })) + return move; + + // 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 QCHECKS: - while (cur < endMoves) - { - move = *cur++; - if (move != ttMove) - return move; - } - break; - - default: - assert(false); + case QCHECK: + return select(Any); } - return MOVE_NONE; + assert(false); + return MOVE_NONE; // Silence warning }