X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovepick.cpp;h=901aa60e5625c766b797fd88d4dec2888b24ac69;hp=a562662e359e514d878b17879dcd18395d940553;hb=337ec0f3d0b402782c3704cc251c209393047dd9;hpb=0855d93de8cf7c68af616a2d5f384a7632470895 diff --git a/src/movepick.cpp b/src/movepick.cpp index a562662e..901aa60e 100644 --- a/src/movepick.cpp +++ b/src/movepick.cpp @@ -52,7 +52,7 @@ namespace { CACHE_LINE_ALIGNMENT const uint8_t MainSearchPhaseTable[] = { PH_TT_MOVES, PH_GOOD_CAPTURES, PH_KILLERS, PH_NONCAPTURES, PH_BAD_CAPTURES, PH_STOP}; - const uint8_t EvasionsPhaseTable[] = { PH_EVASIONS, PH_STOP}; + const uint8_t EvasionsPhaseTable[] = { PH_TT_MOVES, PH_EVASIONS, PH_STOP}; const uint8_t QsearchWithChecksPhaseTable[] = { PH_TT_MOVES, PH_QCAPTURES, PH_QCHECKS, PH_STOP}; const uint8_t QsearchWithoutChecksPhaseTable[] = { PH_TT_MOVES, PH_QCAPTURES, PH_STOP}; } @@ -74,10 +74,11 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h, SearchStack* ss) : pos(p), H(h) { int searchTT = ttm; ttMoves[0].move = ttm; - finished = false; lastBadCapture = badCaptures; - if (ss) + pinned = p.pinned_pieces(pos.side_to_move()); + + if (ss && !p.is_check()) { ttMoves[1].move = (ss->mateKiller == ttm)? MOVE_NONE : ss->mateKiller; searchTT |= ttMoves[1].move; @@ -86,21 +87,24 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d, } else ttMoves[1].move = killers[0].move = killers[1].move = MOVE_NONE; - Color us = pos.side_to_move(); - - dc = p.discovered_check_candidates(us); - pinned = p.pinned_pieces(us); - if (p.is_check()) phasePtr = EvasionsPhaseTable; else if (d > Depth(0)) - phasePtr = MainSearchPhaseTable + !searchTT; + phasePtr = MainSearchPhaseTable; else if (d == Depth(0)) - phasePtr = QsearchWithChecksPhaseTable + !searchTT; + phasePtr = QsearchWithChecksPhaseTable; else - phasePtr = QsearchWithoutChecksPhaseTable + !searchTT; + { + phasePtr = QsearchWithoutChecksPhaseTable; + + // 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.move_is_capture_or_promotion(ttm)) + searchTT = ttMoves[0].move = MOVE_NONE; + } - phasePtr--; + phasePtr += !searchTT - 1; go_next_phase(); } @@ -145,7 +149,7 @@ void MovePicker::go_next_phase() { case PH_EVASIONS: assert(pos.is_check()); lastMove = generate_evasions(pos, moves); - score_evasions(); + score_evasions_or_checks(); return; case PH_QCAPTURES: @@ -154,12 +158,12 @@ void MovePicker::go_next_phase() { return; case PH_QCHECKS: - // Perhaps we should order moves move here? FIXME - lastMove = generate_non_capture_checks(pos, moves, dc); + lastMove = generate_non_capture_checks(pos, moves); + score_evasions_or_checks(); return; case PH_STOP: - lastMove = curMove + 1; // hack to be friendly for get_next_move() + lastMove = curMove + 1; // Avoids another go_next_phase() call return; default: @@ -209,7 +213,6 @@ void MovePicker::score_noncaptures() { Move m; Piece piece; Square from, to; - int hs; for (MoveStack* cur = moves; cur != lastMove; cur++) { @@ -217,32 +220,26 @@ void MovePicker::score_noncaptures() { from = move_from(m); to = move_to(m); piece = pos.piece_on(from); - hs = H.move_ordering_score(piece, to); - - // Ensure history is always preferred to pst - if (hs > 0) - hs += 1000; - - // pst based scoring - cur->score = hs + pos.pst_delta(piece, from, to); + cur->score = H.move_ordering_score(piece, to); } } -void MovePicker::score_evasions() { - // Always try ttMove as first. Then 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. +void MovePicker::score_evasions_or_checks() { + // 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. Move m; int seeScore; + // Skip if we don't have at least two moves to order + if (lastMove < moves + 2) + return; + for (MoveStack* cur = moves; cur != lastMove; cur++) { m = cur->move; - if (m == ttMoves[0].move) - cur->score = 2 * HistoryMax; - else if ((seeScore = pos.see_sign(m)) < 0) + if ((seeScore = pos.see_sign(m)) < 0) cur->score = seeScore; else if (pos.move_is_capture(m)) cur->score = pos.midgame_value_of_piece_on(move_to(m)) @@ -257,12 +254,11 @@ void MovePicker::score_evasions() { /// 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::get_next_move() { - assert(!pos.is_check() || *phasePtr == PH_EVASIONS || *phasePtr == PH_STOP); - assert( pos.is_check() || *phasePtr != PH_EVASIONS); - Move move; while (true) @@ -323,11 +319,6 @@ Move MovePicker::get_next_move() { return move; case PH_EVASIONS: - move = pick_best(curMove++, lastMove).move; - if (pos.pl_move_is_legal(move, pinned)) - return move; - break; - case PH_QCAPTURES: move = pick_best(curMove++, lastMove).move; if ( move != ttMoves[0].move @@ -354,21 +345,3 @@ Move MovePicker::get_next_move() { } } -/// A variant of get_next_move() which takes a lock as a parameter, used to -/// prevent multiple threads from picking the same move at a split point. - -Move MovePicker::get_next_move(Lock &lock) { - - lock_grab(&lock); - if (finished) - { - lock_release(&lock); - return MOVE_NONE; - } - Move m = get_next_move(); - if (m == MOVE_NONE) - finished = true; - - lock_release(&lock); - return m; -}