X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovepick.cpp;h=1b84f14ee83614ca1995e78b50f38d5e94ce8054;hp=3da4247a29e3cdff10de95c06838b7ddb173ae1c;hb=04ac1bcabefaa5b6895b8c20c3c6e3ba7e3a5a61;hpb=e25de55faca30c2196612fcb208d88802ad29bae diff --git a/src/movepick.cpp b/src/movepick.cpp index 3da4247a..1b84f14e 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, + MAIN_SEARCH, TT_MOVE_S1, CAPTURES_S1, KILLERS_S1, QUIETS_1_S1, + QUIETS_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 + CAPTURES_AND_CHECKS, TT_MOVE_S3, CAPTURES_S3, QUIET_CHECKS_S3, STOP_S3, + CAPTURES, TT_MOVE_S4, CAPTURES_S4, STOP_S4, + PROBCUT, TT_MOVE_S5, CAPTURES_S5, STOP_S5, + RECAPTURES, CAPTURES_S6, STOP_S6 }; // 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 @@ -60,16 +59,16 @@ 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 = 0; + badCaptures = moves + MAX_MOVES; + if (p.in_check()) - { - killers[0].move = killers[1].move = MOVE_NONE; phase = EVASIONS; - } + else { killers[0].move = ss->killers[0]; @@ -87,12 +86,11 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h, } ttMove = (ttm && pos.is_pseudo_legal(ttm) ? ttm : MOVE_NONE); - phase += int(ttMove == MOVE_NONE); - go_next_phase(); + phase += (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(0), lastMove(0) { assert(d <= DEPTH_ZERO); @@ -106,31 +104,31 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h, S { phase = CAPTURES; - // 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 = RECAPTURES - 1; + recaptureSquare = sq; ttm = MOVE_NONE; } ttMove = (ttm && pos.is_pseudo_legal(ttm) ? ttm : MOVE_NONE); - phase += int(ttMove == MOVE_NONE); - go_next_phase(); + phase += (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 parentCapture) : pos(p), H(h) { assert (!pos.in_check()); // In ProbCut we consider only captures better than parent's move captureThreshold = PieceValueMidgame[Piece(parentCapture)]; + curMove = lastMove = 0; phase = PROBCUT; if ( ttm != MOVE_NONE @@ -138,85 +136,7 @@ MovePicker::MovePicker(const Position& p, Move ttm, const History& h, PieceType ttm = MOVE_NONE; 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; - - default: - assert(false); - } + phase += (ttMove == MOVE_NONE); } @@ -241,7 +161,6 @@ 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; @@ -267,14 +186,12 @@ void MovePicker::score_noncaptures() { } 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 +208,72 @@ void MovePicker::score_evasions() { } } + +/// MovePicker::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::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: + lastMove = curMove + 1; + return; + + 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: + // 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 QUIET_CHECKS_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 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 +288,31 @@ Move MovePicker::next_move() { while (true) { while (curMove == lastMove) - go_next_phase(); + next_phase(); 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 TT_MOVE_S1: case TT_MOVE_S2: case TT_MOVE_S3: case TT_MOVE_S4: case TT_MOVE_S5: 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) + int seeScore = pos.see_sign(move); + if (seeScore >= captureThreshold) return move; // Losing capture, move it to the tail of the array (--badCaptures)->move = move; - badCaptures->score = seeValue; + badCaptures->score = seeScore; } 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 +322,8 @@ 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 @@ -362,27 +336,32 @@ Move MovePicker::next_move() { return move; case EVASIONS_S2: - case QCAPTURES_S3: - case QCAPTURES_S4: + 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_S1: case STOP_S2: case STOP_S3: case STOP_S4: case STOP_S5: case STOP_S6: return MOVE_NONE; default: