X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovepick.cpp;h=0be426ab659b969b8073b0bb5c8c528f911a2451;hp=3da4247a29e3cdff10de95c06838b7ddb173ae1c;hb=5bb766e826af935b159cbd2ab9c59b279930dc5e;hpb=e25de55faca30c2196612fcb208d88802ad29bae diff --git a/src/movepick.cpp b/src/movepick.cpp index 3da4247a..0be426ab 100644 --- a/src/movepick.cpp +++ b/src/movepick.cpp @@ -23,26 +23,24 @@ #include "movegen.h" #include "movepick.h" -#include "search.h" -#include "types.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) @@ -52,7 +50,8 @@ 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 @@ -60,18 +59,20 @@ namespace { 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; assert(d > DEPTH_ZERO); + captureThreshold = 0; + curMove = lastMove = moves; + lastBadCapture = moves + MAX_MOVES - 1; + 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]; @@ -82,141 +83,59 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h, // 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 = PieceValueMidgame[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; - - 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; + if (ttMove && (!pos.is_capture(ttMove) || pos.see(ttMove) <= captureThreshold)) + ttMove = MOVE_NONE; - default: - assert(false); - } + lastMove += (ttMove != MOVE_NONE); } @@ -241,7 +160,6 @@ 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; @@ -249,32 +167,28 @@ void MovePicker::score_captures() { - type_of(pos.piece_moved(m)); if (is_promotion(m)) - cur->score += PieceValueMidgame[Piece(promotion_piece_type(m))]; + cur->score += PieceValueMidgame[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; @@ -291,6 +205,67 @@ void MovePicker::score_evasions() { } } + +/// 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 @@ -305,40 +280,28 @@ Move MovePicker::next_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 @@ -348,8 +311,7 @@ Move MovePicker::next_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 +320,33 @@ 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: