X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovepick.cpp;h=1ec56c2f700a7c2a30bedd371af100fc6a29e9ec;hp=9dd91f278df644f8727ae4e7d66c634248177133;hb=1e586288ca4a0ae567c8d9b9b77e804f25fe6719;hpb=55758344d3ccf49353bcd8f3a06a4553ff1b753a diff --git a/src/movepick.cpp b/src/movepick.cpp index 9dd91f27..1ec56c2f 100644 --- a/src/movepick.cpp +++ b/src/movepick.cpp @@ -2,13 +2,13 @@ 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) 2015-2016 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad Stockfish is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. - Stockfish is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the @@ -26,13 +26,12 @@ namespace { enum Stages { - MAIN_SEARCH, GOOD_CAPTURES, KILLERS, GOOD_QUIETS, BAD_QUIETS, BAD_CAPTURES, - EVASION, ALL_EVASIONS, - QSEARCH_WITH_CHECKS, QCAPTURES_1, CHECKS, - QSEARCH_WITHOUT_CHECKS, QCAPTURES_2, - PROBCUT, PROBCUT_CAPTURES, - RECAPTURE, RECAPTURES, - STOP + MAIN_SEARCH, CAPTURES_INIT, GOOD_CAPTURES, KILLERS, COUNTERMOVE, QUIET_INIT, QUIET, BAD_CAPTURES, + EVASION, EVASIONS_INIT, ALL_EVASIONS, + PROBCUT, PROBCUT_INIT, PROBCUT_CAPTURES, + QSEARCH_WITH_CHECKS, QCAPTURES_1_INIT, QCAPTURES_1, QCHECKS, + QSEARCH_NO_CHECKS, QCAPTURES_2_INIT, QCAPTURES_2, + QSEARCH_RECAPTURES, QRECAPTURES }; // Our insertion sort, which is guaranteed to be stable, as it should be @@ -51,7 +50,7 @@ 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. + // are few moves, e.g., the possible captures. Move pick_best(ExtMove* begin, ExtMove* end) { std::swap(*begin, *std::max_element(begin, end)); @@ -64,23 +63,24 @@ 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 +/// search captures, promotions, and some checks) and how important good move /// ordering is at the current node. -MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const HistoryStats& h, - const CounterMovesHistoryStats& cmh, Move cm, Search::Stack* s) - : pos(p), history(h), counterMovesHistory(cmh), ss(s), countermove(cm), depth(d) { +MovePicker::MovePicker(const Position& p, Move ttm, Depth d, Search::Stack* s) + : pos(p), ss(s), depth(d) { assert(d > DEPTH_ZERO); + Square prevSq = to_sq((ss-1)->currentMove); + countermove = pos.this_thread()->counterMoves[pos.piece_on(prevSq)][prevSq]; + stage = pos.checkers() ? EVASION : MAIN_SEARCH; ttMove = ttm && pos.pseudo_legal(ttm) ? ttm : MOVE_NONE; - endMoves += (ttMove != MOVE_NONE); + stage += (ttMove == MOVE_NONE); } -MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const HistoryStats& h, - const CounterMovesHistoryStats& cmh, Square s) - : pos(p), history(h), counterMovesHistory(cmh) { +MovePicker::MovePicker(const Position& p, Move ttm, Depth d, Square s) + : pos(p) { assert(d <= DEPTH_ZERO); @@ -91,22 +91,21 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const HistoryStats& stage = QSEARCH_WITH_CHECKS; else if (d > DEPTH_QS_RECAPTURES) - stage = QSEARCH_WITHOUT_CHECKS; + stage = QSEARCH_NO_CHECKS; else { - stage = RECAPTURE; + stage = QSEARCH_RECAPTURES; recaptureSquare = s; - ttm = MOVE_NONE; + return; } ttMove = ttm && pos.pseudo_legal(ttm) ? ttm : MOVE_NONE; - endMoves += (ttMove != MOVE_NONE); + stage += (ttMove == MOVE_NONE); } -MovePicker::MovePicker(const Position& p, Move ttm, const HistoryStats& h, - const CounterMovesHistoryStats& cmh, Value th) - : pos(p), history(h), counterMovesHistory(cmh), threshold(th) { +MovePicker::MovePicker(const Position& p, Move ttm, Value th) + : pos(p), threshold(th) { assert(!pos.checkers()); @@ -118,7 +117,7 @@ MovePicker::MovePicker(const Position& p, Move ttm, const HistoryStats& h, && pos.capture(ttm) && pos.see(ttm) > threshold ? ttm : MOVE_NONE; - endMoves += (ttMove != MOVE_NONE); + stage += (ttMove == MOVE_NONE); } @@ -128,9 +127,9 @@ template<> void MovePicker::score() { // Winning and equal captures in the main search are ordered by MVV, preferring // captures near our home rank. Surprisingly, this appears to perform slightly - // better than SEE based move ordering: exchanging big pieces before capturing + // better than SEE-based move ordering: exchanging big pieces before capturing // a hanging piece probably helps to reduce the subtree size. - // In main search we want to push captures with negative SEE values to the + // In the main search we want to push captures with negative SEE values to the // badCaptures[] array, but instead of doing it now we delay until the move // has been picked up, saving some SEE calls in case we get a cutoff. for (auto& m : *this) @@ -141,96 +140,36 @@ void MovePicker::score() { template<> void MovePicker::score() { - Square prevSq = to_sq((ss-1)->currentMove); - const HistoryStats& cmh = counterMovesHistory[pos.piece_on(prevSq)][prevSq]; + const HistoryStats& history = pos.this_thread()->history; + const FromToStats& fromTo = pos.this_thread()->fromTo; + + const CounterMoveStats* cm = (ss-1)->counterMoves; + const CounterMoveStats* fm = (ss-2)->counterMoves; + const CounterMoveStats* f2 = (ss-4)->counterMoves; + + Color c = pos.side_to_move(); for (auto& m : *this) - m.value = history[pos.moved_piece(m)][to_sq(m)] - + cmh[pos.moved_piece(m)][to_sq(m)]; + m.value = history[pos.moved_piece(m)][to_sq(m)] + + (cm ? (*cm)[pos.moved_piece(m)][to_sq(m)] : VALUE_ZERO) + + (fm ? (*fm)[pos.moved_piece(m)][to_sq(m)] : VALUE_ZERO) + + (f2 ? (*f2)[pos.moved_piece(m)][to_sq(m)] : VALUE_ZERO) + + fromTo.get(c, m); } template<> void MovePicker::score() { - // Try winning and equal captures captures ordered by MVV/LVA, then non-captures - // ordered by history value, then bad-captures and quiet moves with a negative - // SEE ordered by SEE value. - Value see; + // Try captures ordered by MVV/LVA, then non-captures ordered by history value + const HistoryStats& history = pos.this_thread()->history; + const FromToStats& fromTo = pos.this_thread()->fromTo; + Color c = pos.side_to_move(); for (auto& m : *this) - if ((see = pos.see_sign(m)) < VALUE_ZERO) - m.value = see - HistoryStats::Max; // At the bottom - - else if (pos.capture(m)) + if (pos.capture(m)) m.value = PieceValue[MG][pos.piece_on(to_sq(m))] - Value(type_of(pos.moved_piece(m))) + HistoryStats::Max; else - m.value = history[pos.moved_piece(m)][to_sq(m)]; -} - - -/// generate_next_stage() generates, scores and sorts the next bunch of moves, -/// when there are no more moves to try for the current stage. - -void MovePicker::generate_next_stage() { - - assert(stage != STOP); - - cur = moves; - - switch (++stage) { - - case GOOD_CAPTURES: case QCAPTURES_1: case QCAPTURES_2: - case PROBCUT_CAPTURES: case RECAPTURES: - endMoves = generate(pos, moves); - score(); - break; - - case KILLERS: - killers[0] = ss->killers[0]; - killers[1] = ss->killers[1]; - killers[2] = countermove; - cur = killers; - endMoves = cur + 2 + (countermove != killers[0] && countermove != killers[1]); - break; - - case GOOD_QUIETS: - endQuiets = endMoves = generate(pos, moves); - score(); - endMoves = std::partition(cur, endMoves, [](const ExtMove& m) { return m.value > VALUE_ZERO; }); - insertion_sort(cur, endMoves); - break; - - case BAD_QUIETS: - cur = endMoves; - endMoves = endQuiets; - if (depth >= 3 * ONE_PLY) - insertion_sort(cur, endMoves); - break; - - case BAD_CAPTURES: - // Just pick them in reverse order to get correct ordering - cur = moves + MAX_MOVES - 1; - endMoves = endBadCaptures; - break; - - case ALL_EVASIONS: - endMoves = generate(pos, moves); - if (endMoves - moves > 1) - score(); - break; - - case CHECKS: - endMoves = generate(pos, moves); - break; - - case EVASION: case QSEARCH_WITH_CHECKS: case QSEARCH_WITHOUT_CHECKS: - case PROBCUT: case RECAPTURE: case STOP: - stage = STOP; - break; - - default: - assert(false); - } + m.value = history[pos.moved_piece(m)][to_sq(m)] + fromTo.get(c, m); } @@ -243,80 +182,170 @@ Move MovePicker::next_move() { Move move; - while (true) - { - while (cur == endMoves && stage != STOP) - generate_next_stage(); + switch (stage) { - switch (stage) { + case MAIN_SEARCH: case EVASION: case QSEARCH_WITH_CHECKS: + case QSEARCH_NO_CHECKS: case PROBCUT: + ++stage; + return ttMove; - case MAIN_SEARCH: case EVASION: case QSEARCH_WITH_CHECKS: - case QSEARCH_WITHOUT_CHECKS: case PROBCUT: - ++cur; - return ttMove; + case CAPTURES_INIT: + endBadCaptures = cur = moves; + endMoves = generate(pos, cur); + score(); + ++stage; - case GOOD_CAPTURES: + case GOOD_CAPTURES: + while (cur < endMoves) + { move = pick_best(cur++, endMoves); if (move != ttMove) { if (pos.see_sign(move) >= VALUE_ZERO) return move; - // Losing capture, move it to the tail of the array - *endBadCaptures-- = move; + // Losing capture, move it to the beginning of the array + *endBadCaptures++ = move; } - break; + } - case KILLERS: - move = *cur++; - if ( move != MOVE_NONE - && move != ttMove - && pos.pseudo_legal(move) - && !pos.capture(move)) - return move; - break; + ++stage; + move = ss->killers[0]; // First killer move + if ( move != MOVE_NONE + && move != ttMove + && pos.pseudo_legal(move) + && !pos.capture(move)) + return move; - case GOOD_QUIETS: case BAD_QUIETS: + case KILLERS: + ++stage; + move = ss->killers[1]; // Second killer move + if ( move != MOVE_NONE + && move != ttMove + && pos.pseudo_legal(move) + && !pos.capture(move)) + return move; + + case COUNTERMOVE: + ++stage; + move = countermove; + if ( move != MOVE_NONE + && move != ttMove + && move != ss->killers[0] + && move != ss->killers[1] + && pos.pseudo_legal(move) + && !pos.capture(move)) + return move; + + case QUIET_INIT: + cur = endBadCaptures; + endMoves = generate(pos, cur); + score(); + if (depth < 3 * ONE_PLY) + { + ExtMove* goodQuiet = std::partition(cur, endMoves, [](const ExtMove& m) + { return m.value > VALUE_ZERO; }); + insertion_sort(cur, goodQuiet); + } else + insertion_sort(cur, endMoves); + ++stage; + + case QUIET: + while (cur < endMoves) + { move = *cur++; if ( move != ttMove - && move != killers[0] - && move != killers[1] - && move != killers[2]) + && move != ss->killers[0] + && move != ss->killers[1] + && move != countermove) return move; - break; + } + ++stage; + cur = moves; // Point to beginning of bad captures - case BAD_CAPTURES: - return *cur--; + case BAD_CAPTURES: + if (cur < endBadCaptures) + return *cur++; + break; + + case EVASIONS_INIT: + cur = moves; + endMoves = generate(pos, cur); + if (endMoves - cur - (ttMove != MOVE_NONE) > 1) + score(); + ++stage; - case ALL_EVASIONS: case QCAPTURES_1: case QCAPTURES_2: + case ALL_EVASIONS: + while (cur < endMoves) + { move = pick_best(cur++, endMoves); if (move != ttMove) return move; - break; + } + break; - case PROBCUT_CAPTURES: - move = pick_best(cur++, endMoves); - if (move != ttMove && pos.see(move) > threshold) - return move; - break; + case PROBCUT_INIT: + cur = moves; + endMoves = generate(pos, cur); + score(); + ++stage; - case RECAPTURES: + case PROBCUT_CAPTURES: + while (cur < endMoves) + { move = pick_best(cur++, endMoves); - if (to_sq(move) == recaptureSquare) + if ( move != ttMove + && pos.see(move) > threshold) return move; - break; + } + break; - case CHECKS: - move = *cur++; + case QCAPTURES_1_INIT: case QCAPTURES_2_INIT: + cur = moves; + endMoves = generate(pos, cur); + score(); + ++stage; + + case QCAPTURES_1: case QCAPTURES_2: + while (cur < endMoves) + { + move = pick_best(cur++, endMoves); if (move != ttMove) return move; + } + if (stage == QCAPTURES_2) break; + cur = moves; + endMoves = generate(pos, cur); + ++stage; + + case QCHECKS: + while (cur < endMoves) + { + move = cur++->move; + if (move != ttMove) + return move; + } + break; - case STOP: - return MOVE_NONE; + case QSEARCH_RECAPTURES: + cur = moves; + endMoves = generate(pos, cur); + score(); + ++stage; - default: - assert(false); + case QRECAPTURES: + while (cur < endMoves) + { + move = pick_best(cur++, endMoves); + if (to_sq(move) == recaptureSquare) + return move; } + break; + + default: + assert(false); } + + return MOVE_NONE; }