X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovepick.cpp;h=0ceeb8eaf60794bfc2df804468955131ef2a9a76;hp=c013042aecf9032c8286580f5bb26b8f8764b15b;hb=40cb0f076a62115af030c4524825d9ba73d61023;hpb=bd59560480cc4f43a4ba75dc827ba27bcebb92dd diff --git a/src/movepick.cpp b/src/movepick.cpp index c013042a..0ceeb8ea 100644 --- a/src/movepick.cpp +++ b/src/movepick.cpp @@ -1,8 +1,6 @@ /* Stockfish, a UCI chess playing engine derived from Glaurung 2.1 - Copyright (C) 2004-2008 Tord Romstad (Glaurung author) - Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad - Copyright (C) 2015-2018 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad + Copyright (C) 2004-2021 The Stockfish developers (see AUTHORS file) Stockfish is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -25,15 +23,12 @@ namespace { enum Stages { - MAIN_TT, CAPTURE_INIT, GOOD_CAPTURE, KILLER0, KILLER1, COUNTERMOVE, QUIET_INIT, QUIET, BAD_CAPTURE, + 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_move() - 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) { @@ -59,45 +54,40 @@ namespace { /// 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, Move* killers_p) - : pos(p), mainHistory(mh), captureHistory(cph), contHistory(ch), - refutations{killers_p[0], killers_p[1], cm}, depth(d){ +MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHistory* mh, const LowPlyHistory* lp, + const CapturePieceToHistory* cph, const PieceToHistory** ch, Move cm, const Move* killers, int pl) + : pos(p), mainHistory(mh), lowPlyHistory(lp), captureHistory(cph), continuationHistory(ch), + ttMove(ttm), refutations{{killers[0], 0}, {killers[1], 0}, {cm, 0}}, depth(d), ply(pl) { - assert(d > DEPTH_ZERO); + assert(d > 0); - stage = pos.checkers() ? EVASION_TT : MAIN_TT; - ttMove = ttm && pos.pseudo_legal(ttm) ? ttm : MOVE_NONE; - stage += (ttMove == MOVE_NONE); + stage = (pos.checkers() ? EVASION_TT : MAIN_TT) + + !(ttm && pos.pseudo_legal(ttm)); } /// MovePicker constructor for quiescence search MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const ButterflyHistory* mh, - const CapturePieceToHistory* cph, Square rs) - : pos(p), mainHistory(mh), captureHistory(cph), recaptureSquare(rs), depth(d) { + const CapturePieceToHistory* cph, const PieceToHistory** ch, Square rs) + : pos(p), mainHistory(mh), captureHistory(cph), continuationHistory(ch), ttMove(ttm), recaptureSquare(rs), depth(d) { - assert(d <= DEPTH_ZERO); + assert(d <= 0); - 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); + stage = (pos.checkers() ? EVASION_TT : QSEARCH_TT) + + !( ttm + && (pos.checkers() || depth > DEPTH_QS_RECAPTURES || to_sq(ttm) == recaptureSquare) + && pos.pseudo_legal(ttm)); } -/// 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) { + : pos(p), captureHistory(cph), ttMove(ttm), threshold(th) { assert(!pos.checkers()); - stage = PROBCUT_TT; - ttMove = ttm - && pos.pseudo_legal(ttm) - && pos.capture(ttm) - && pos.see_ge(ttm, threshold) ? ttm : MOVE_NONE; - stage += (ttMove == MOVE_NONE); + stage = PROBCUT_TT + !(ttm && pos.capture(ttm) + && pos.pseudo_legal(ttm) + && pos.see_ge(ttm, threshold)); } /// MovePicker::score() assigns a numerical value to each move in a list, used @@ -109,15 +99,17 @@ void MovePicker::score() { static_assert(Type == CAPTURES || Type == QUIETS || Type == EVASIONS, "Wrong type"); for (auto& m : *this) - if (Type == CAPTURES) - m.value = PieceValue[MG][pos.piece_on(to_sq(m))] + if constexpr (Type == CAPTURES) + m.value = int(PieceValue[MG][pos.piece_on(to_sq(m))]) * 6 + (*captureHistory)[pos.moved_piece(m)][to_sq(m)][type_of(pos.piece_on(to_sq(m)))]; - 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)]; + else if constexpr (Type == QUIETS) + m.value = (*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)] + + (ply < MAX_LPH ? std::min(4, depth / 3) * (*lowPlyHistory)[ply][from_to(m)] : 0); else // Type == EVASIONS { @@ -125,30 +117,33 @@ 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)] + + 2 * (*continuationHistory[0])[pos.moved_piece(m)][to_sq(m)] + - (1 << 28); } } -/// MovePicker::select_move() returns the next move satisfying a predicate function -template -Move MovePicker::select_move(Pred filter) { +/// MovePicker::select() returns the next move satisfying a predicate function. +/// It never returns the TT move. +template +Move MovePicker::select(Pred filter) { while (cur < endMoves) { - if (T == BEST_SCORE) + if (T == Best) std::swap(*cur, *std::max_element(cur, endMoves)); - move = *cur++; + if (*cur != ttMove && filter()) + return *cur++; - if (move != ttMove && filter()) - return move; + cur++; } - return move = MOVE_NONE; + 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. It picks the move with the highest score from a list of generated moves. +/// 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: @@ -164,95 +159,105 @@ top: case CAPTURE_INIT: case PROBCUT_INIT: case QCAPTURE_INIT: - endBadCaptures = cur = moves; + cur = endBadCaptures = moves; endMoves = generate(pos, cur); + score(); ++stage; goto top; case GOOD_CAPTURE: - if (select_move([&](){ 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; + if (select([&](){ + return pos.see_ge(*cur, Value(-69 * cur->value / 1024)) ? + // 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] == refutations[2] - || refutations[1] == refutations[2]) - refutations[2] = MOVE_NONE; + 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 */ + [[fallthrough]]; - case KILLER0: - case KILLER1: - case COUNTERMOVE: - while (stage <= COUNTERMOVE) + case QUIET_INIT: + if (!skipQuiets) { - move = refutations[ stage++ - KILLER0]; - if ( move != MOVE_NONE - && move != ttMove - && pos.pseudo_legal(move) - && !pos.capture(move)) - return move; + cur = endBadCaptures; + endMoves = generate(pos, cur); + + score(); + partial_insertion_sort(cur, endMoves, -3000 * depth); } - /* fallthrough */ - case QUIET_INIT: - cur = endBadCaptures; - endMoves = generate(pos, cur); - score(); - partial_insertion_sort(cur, endMoves, -4000 * depth / ONE_PLY); ++stage; - /* fallthrough */ + [[fallthrough]]; case QUIET: if ( !skipQuiets - && select_move([&](){return move != refutations[0] - && move != refutations[1] - && move != refutations[2];})) - return move; + && 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; - // Point to beginning and end of bad captures - cur = moves, endMoves = endBadCaptures; ++stage; - /* fallthrough */ + [[fallthrough]]; case BAD_CAPTURE: - return select_move(Any); + return select([](){ return true; }); case EVASION_INIT: cur = moves; endMoves = generate(pos, cur); + score(); ++stage; - /* fallthrough */ + [[fallthrough]]; case EVASION: - return select_move(Any); + return select([](){ return true; }); case PROBCUT: - return select_move([&](){ return pos.see_ge(move, threshold); }); + return select([&](){ return pos.see_ge(*cur, threshold); }); case QCAPTURE: - if (select_move([&](){ return depth > DEPTH_QS_RECAPTURES - || to_sq(move) == recaptureSquare; })) - return move; + 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 */ + [[fallthrough]]; case QCHECK_INIT: cur = moves; endMoves = generate(pos, cur); + ++stage; - /* fallthrough */ + [[fallthrough]]; case QCHECK: - return select_move(Any); + return select([](){ return true; }); } assert(false);