X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovepick.cpp;h=b09647953a7fe50a6647d0c21668dcea340d20d6;hp=3da4247a29e3cdff10de95c06838b7ddb173ae1c;hb=b84af67f4c88f3e3f7b61bf2035475f79fb3e62e;hpb=e25de55faca30c2196612fcb208d88802ad29bae diff --git a/src/movepick.cpp b/src/movepick.cpp index 3da4247a..b0964795 100644 --- a/src/movepick.cpp +++ b/src/movepick.cpp @@ -23,26 +23,25 @@ #include "movegen.h" #include "movepick.h" -#include "search.h" -#include "types.h" +#include "thread.h" namespace { enum Sequencer { - MAIN_SEARCH, TT_MOVE_S1, GOOD_CAPTURES_S1, KILLERS_S1, NONCAPTURES_1_S1, - NONCAPTURES_2_S1, BAD_CAPTURES_S1, STOP_S1, - EVASIONS, TT_MOVE_S2, EVASIONS_S2, STOP_S2, - CAPTURES_AND_CHECKS, TT_MOVE_S3, QCAPTURES_S3, QCHECKS_S3, STOP_S3, - CAPTURES, TT_MOVE_S4, QCAPTURES_S4, STOP_S4, - RECAPTURES, TT_MOVE_S5, RECAPTURES_S5, STOP_S5, - PROBCUT, TT_MOVE_S6, GOOD_CAPTURES_S6, STOP_S6 + MAIN_SEARCH, CAPTURES_S1, KILLERS_S1, QUIETS_1_S1, QUIETS_2_S1, BAD_CAPTURES_S1, + EVASION, EVASIONS_S2, + QSEARCH_0, CAPTURES_S3, QUIET_CHECKS_S3, + QSEARCH_1, CAPTURES_S4, + PROBCUT, CAPTURES_S5, + RECAPTURE, CAPTURES_S6, + STOP }; // Unary predicate used by std::partition to split positive scores from remaining // ones so to sort separately the two sets, and with the second sort delayed. inline bool has_positive_score(const MoveStack& move) { return move.score > 0; } - // Picks and pushes to the front the best move in range [firstMove, lastMove), + // Picks and moves to the front the best move in the range [firstMove, lastMove), // it is faster than sorting all the moves in advance when moves are few, as // normally are the possible captures. inline MoveStack* pick_best(MoveStack* firstMove, MoveStack* lastMove) @@ -52,171 +51,93 @@ namespace { } } -/// Constructors for the MovePicker class. As arguments we pass information + +/// 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 about how important good /// move ordering is at the current node. MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h, - Search::Stack* ss, Value beta) : pos(p), H(h), depth(d) { - captureThreshold = 0; - badCaptures = moves + MAX_MOVES; + Search::Stack* s, Value beta) : pos(p), H(h), depth(d) { assert(d > DEPTH_ZERO); + captureThreshold = 0; + curMove = lastMove = moves; + lastBadCapture = moves + MAX_MOVES - 1; + ss = s; + if (p.in_check()) - { - killers[0].move = killers[1].move = MOVE_NONE; - phase = EVASIONS; - } + phase = EVASION; + else { + phase = MAIN_SEARCH; + killers[0].move = ss->killers[0]; killers[1].move = ss->killers[1]; // Consider sligtly negative captures as good if at low depth and far from beta - if (ss && ss->eval < beta - PawnValueMidgame && d < 3 * ONE_PLY) - captureThreshold = -PawnValueMidgame; + if (ss && ss->eval < beta - PawnValueMg && d < 3 * ONE_PLY) + captureThreshold = -PawnValueMg; // Consider negative captures as good if still enough to reach beta else if (ss && ss->eval > beta) captureThreshold = beta - ss->eval; - - phase = MAIN_SEARCH; } ttMove = (ttm && pos.is_pseudo_legal(ttm) ? ttm : MOVE_NONE); - phase += int(ttMove == MOVE_NONE); - go_next_phase(); + lastMove += (ttMove != MOVE_NONE); } -MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h, Square recaptureSq) - : pos(p), H(h) { +MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h, + Square sq) : pos(p), H(h), curMove(moves), lastMove(moves) { assert(d <= DEPTH_ZERO); if (p.in_check()) - phase = EVASIONS; + phase = EVASION; - else if (d >= DEPTH_QS_CHECKS) - phase = CAPTURES_AND_CHECKS; + else if (d > DEPTH_QS_NO_CHECKS) + phase = QSEARCH_0; - else if (d >= DEPTH_QS_RECAPTURES) + else if (d > DEPTH_QS_RECAPTURES) { - phase = CAPTURES; + phase = QSEARCH_1; - // Skip TT move if is not a capture or a promotion, this avoids - // qsearch tree explosion due to a possible perpetual check or - // similar rare cases when TT table is full. - if (ttm != MOVE_NONE && !pos.is_capture_or_promotion(ttm)) + // Skip TT move if is not a capture or a promotion, this avoids qsearch + // tree explosion due to a possible perpetual check or similar rare cases + // when TT table is full. + if (ttm && !pos.is_capture_or_promotion(ttm)) ttm = MOVE_NONE; } else { - phase = RECAPTURES; - recaptureSquare = recaptureSq; + phase = RECAPTURE; + recaptureSquare = sq; ttm = MOVE_NONE; } ttMove = (ttm && pos.is_pseudo_legal(ttm) ? ttm : MOVE_NONE); - phase += int(ttMove == MOVE_NONE); - go_next_phase(); + lastMove += (ttMove != MOVE_NONE); } -MovePicker::MovePicker(const Position& p, Move ttm, const History& h, PieceType parentCapture) - : pos(p), H(h) { +MovePicker::MovePicker(const Position& p, Move ttm, const History& h, PieceType pt) + : pos(p), H(h), curMove(moves), lastMove(moves) { - assert (!pos.in_check()); + assert(!pos.in_check()); - // In ProbCut we consider only captures better than parent's move - captureThreshold = PieceValueMidgame[Piece(parentCapture)]; phase = PROBCUT; - if ( ttm != MOVE_NONE - && (!pos.is_capture(ttm) || pos.see(ttm) <= captureThreshold)) - ttm = MOVE_NONE; - + // In ProbCut we generate only captures better than parent's captured piece + captureThreshold = PieceValue[Mg][pt]; ttMove = (ttm && pos.is_pseudo_legal(ttm) ? ttm : MOVE_NONE); - phase += int(ttMove == MOVE_NONE); - go_next_phase(); -} - - -/// MovePicker::go_next_phase() generates, scores and sorts the next bunch -/// of moves when there are no more moves to try for the current phase. - -void MovePicker::go_next_phase() { - - curMove = moves; - - switch (++phase) { - - case TT_MOVE_S1: case TT_MOVE_S2: case TT_MOVE_S3: - case TT_MOVE_S4: case TT_MOVE_S5: case TT_MOVE_S6: - lastMove = curMove + 1; - return; - - case GOOD_CAPTURES_S1: - case GOOD_CAPTURES_S6: - lastMove = generate(pos, moves); - score_captures(); - return; - - case KILLERS_S1: - curMove = killers; - lastMove = curMove + 2; - return; - - case NONCAPTURES_1_S1: - lastNonCapture = lastMove = generate(pos, moves); - score_noncaptures(); - lastMove = std::partition(curMove, lastMove, has_positive_score); - sort(curMove, lastMove); - return; - case NONCAPTURES_2_S1: - curMove = lastMove; - lastMove = lastNonCapture; - if (depth >= 3 * ONE_PLY) - sort(curMove, lastMove); - return; - - case BAD_CAPTURES_S1: - // Bad captures SEE value is already calculated so just pick - // them in order to get SEE move ordering. - curMove = badCaptures; - lastMove = moves + MAX_MOVES; - return; + if (ttMove && (!pos.is_capture(ttMove) || pos.see(ttMove) <= captureThreshold)) + ttMove = MOVE_NONE; - case EVASIONS_S2: - assert(pos.in_check()); - lastMove = generate(pos, moves); - score_evasions(); - return; - - case QCAPTURES_S3: - case QCAPTURES_S4: - lastMove = generate(pos, moves); - score_captures(); - return; - - case RECAPTURES_S5: - lastMove = generate(pos, moves); - return; - - case QCHECKS_S3: - lastMove = generate(pos, moves); - return; - - case STOP_S1: case STOP_S2: case STOP_S3: - case STOP_S4: case STOP_S5: case STOP_S6: - lastMove = curMove + 1; // Avoid another go_next_phase() call - return; - - default: - assert(false); - } + lastMove += (ttMove != MOVE_NONE); } @@ -241,40 +162,35 @@ void MovePicker::score_captures() { // some SEE calls in case we get a cutoff (idea from Pablo Vazquez). Move m; - // Use MVV/LVA ordering for (MoveStack* cur = moves; cur != lastMove; cur++) { m = cur->move; - cur->score = PieceValueMidgame[pos.piece_on(to_sq(m))] + cur->score = PieceValue[Mg][pos.piece_on(to_sq(m))] - type_of(pos.piece_moved(m)); - if (is_promotion(m)) - cur->score += PieceValueMidgame[Piece(promotion_piece_type(m))]; + if (type_of(m) == PROMOTION) + cur->score += PieceValue[Mg][promotion_type(m)]; } } void MovePicker::score_noncaptures() { Move m; - Square from; for (MoveStack* cur = moves; cur != lastMove; cur++) { m = cur->move; - from = from_sq(m); - cur->score = H.value(pos.piece_on(from), to_sq(m)); + cur->score = H.value(pos.piece_moved(m), to_sq(m)); } } void MovePicker::score_evasions() { - // Try good captures ordered by MVV/LVA, then non-captures if - // destination square is not under attack, ordered by history - // value, and at the end bad-captures and non-captures with a - // negative SEE. This last group is ordered by the SEE score. + // Try good captures ordered by MVV/LVA, then non-captures if destination square + // is not under attack, ordered by history value, then bad-captures and quiet + // moves with a negative SEE. This last group is ordered by the SEE score. Move m; int seeScore; - // Skip if we don't have at least two moves to order if (lastMove < moves + 2) return; @@ -284,72 +200,119 @@ void MovePicker::score_evasions() { if ((seeScore = pos.see_sign(m)) < 0) cur->score = seeScore - History::MaxValue; // Be sure we are at the bottom else if (pos.is_capture(m)) - cur->score = PieceValueMidgame[pos.piece_on(to_sq(m))] + cur->score = PieceValue[Mg][pos.piece_on(to_sq(m))] - type_of(pos.piece_moved(m)) + History::MaxValue; else cur->score = H.value(pos.piece_moved(m), to_sq(m)); } } + +/// MovePicker::generate_next() generates, scores and sorts the next bunch of moves, +/// when there are no more moves to try for the current phase. + +void MovePicker::generate_next() { + + curMove = moves; + + switch (++phase) { + + case CAPTURES_S1: case CAPTURES_S3: case CAPTURES_S4: case CAPTURES_S5: case CAPTURES_S6: + lastMove = generate(pos, moves); + score_captures(); + return; + + case KILLERS_S1: + curMove = killers; + lastMove = curMove + 2; + return; + + case QUIETS_1_S1: + lastQuiet = lastMove = generate(pos, moves); + score_noncaptures(); + lastMove = std::partition(curMove, lastMove, has_positive_score); + sort(curMove, lastMove); + return; + + case QUIETS_2_S1: + curMove = lastMove; + lastMove = lastQuiet; + if (depth >= 3 * ONE_PLY) + sort(curMove, lastMove); + return; + + case BAD_CAPTURES_S1: + // Just pick them in reverse order to get MVV/LVA ordering + curMove = moves + MAX_MOVES - 1; + lastMove = lastBadCapture; + return; + + case EVASIONS_S2: + lastMove = generate(pos, moves); + score_evasions(); + return; + + case QUIET_CHECKS_S3: + lastMove = generate(pos, moves); + return; + + case EVASION: case QSEARCH_0: case QSEARCH_1: case PROBCUT: case RECAPTURE: + phase = STOP; + case STOP: + lastMove = curMove + 1; // Avoid another next_phase() call + return; + + default: + assert(false); + } +} + + /// 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 biggest score from a list /// of generated moves taking care not to return the tt move if has already been -/// searched previously. Note that this function is not thread safe so should be -/// lock protected by caller when accessed through a shared MovePicker object. - -Move MovePicker::next_move() { +/// searched previously. +template<> +Move MovePicker::next_move() { Move move; while (true) { while (curMove == lastMove) - go_next_phase(); + generate_next(); switch (phase) { - case TT_MOVE_S1: case TT_MOVE_S2: case TT_MOVE_S3: - case TT_MOVE_S4: case TT_MOVE_S5: case TT_MOVE_S6: + case MAIN_SEARCH: case EVASION: case QSEARCH_0: case QSEARCH_1: case PROBCUT: curMove++; return ttMove; - break; - case GOOD_CAPTURES_S1: + case CAPTURES_S1: move = pick_best(curMove++, lastMove)->move; if (move != ttMove) { - assert(captureThreshold <= 0); // Otherwise we must use see instead of see_sign + assert(captureThreshold <= 0); // Otherwise we cannot use see_sign() - // Check for a non negative SEE now - int seeValue = pos.see_sign(move); - if (seeValue >= captureThreshold) + if (pos.see_sign(move) >= captureThreshold) return move; // Losing capture, move it to the tail of the array - (--badCaptures)->move = move; - badCaptures->score = seeValue; + (lastBadCapture--)->move = move; } break; - case GOOD_CAPTURES_S6: - move = pick_best(curMove++, lastMove)->move; - if ( move != ttMove - && pos.see(move) > captureThreshold) - return move; - break; - case KILLERS_S1: move = (curMove++)->move; - if ( move != MOVE_NONE - && pos.is_pseudo_legal(move) - && move != ttMove + if ( move != MOVE_NONE + && pos.is_pseudo_legal(move) + && move != ttMove && !pos.is_capture(move)) return move; break; - case NONCAPTURES_1_S1: - case NONCAPTURES_2_S1: + case QUIETS_1_S1: case QUIETS_2_S1: move = (curMove++)->move; if ( move != ttMove && move != killers[0].move @@ -358,31 +321,33 @@ Move MovePicker::next_move() { break; case BAD_CAPTURES_S1: - move = pick_best(curMove++, lastMove)->move; - return move; + return (curMove--)->move; - case EVASIONS_S2: - case QCAPTURES_S3: - case QCAPTURES_S4: + case EVASIONS_S2: case CAPTURES_S3: case CAPTURES_S4: move = pick_best(curMove++, lastMove)->move; if (move != ttMove) return move; break; - case RECAPTURES_S5: - move = (curMove++)->move; + case CAPTURES_S5: + move = pick_best(curMove++, lastMove)->move; + if (move != ttMove && pos.see(move) > captureThreshold) + return move; + break; + + case CAPTURES_S6: + move = pick_best(curMove++, lastMove)->move; if (to_sq(move) == recaptureSquare) return move; break; - case QCHECKS_S3: + case QUIET_CHECKS_S3: move = (curMove++)->move; if (move != ttMove) return move; break; - case STOP_S1: case STOP_S2: case STOP_S3: - case STOP_S4: case STOP_S5: case STOP_S6: + case STOP: return MOVE_NONE; default: @@ -390,3 +355,10 @@ Move MovePicker::next_move() { } } } + + +/// Version of next_move() to use at split point nodes where the move is grabbed +/// from the split point's shared MovePicker object. This function is not thread +/// safe so should be lock protected by the caller. +template<> +Move MovePicker::next_move() { return ss->sp->mp->next_move(); }