X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovepick.cpp;h=ee747c94525cdee18b9f78ea585abd3854cd23e8;hp=c71572e7cf86bead8aa853dd16db512ab329e55d;hb=8a0dd93c56f63de467190145116ed6c5cfd54bc1;hpb=d087b0a34a6aaa0fc31d2fa256b02861d0351256 diff --git a/src/movepick.cpp b/src/movepick.cpp index c71572e7..ee747c94 100644 --- a/src/movepick.cpp +++ b/src/movepick.cpp @@ -26,6 +26,7 @@ #include #include "history.h" +#include "evaluate.h" #include "movegen.h" #include "movepick.h" #include "search.h" @@ -44,7 +45,9 @@ namespace { int MainSearchPhaseIndex; int EvasionsPhaseIndex; int QsearchWithChecksPhaseIndex; + int QsearchNoCapturesPhaseIndex; int QsearchWithoutChecksPhaseIndex; + int NoMovesPhaseIndex; } @@ -62,28 +65,38 @@ namespace { /// search captures, promotions and some checks) and about how important good /// move ordering is at the current node. -MovePicker::MovePicker(const Position& p, bool pvnode, Move ttm, Move mk, - Move k1, Move k2, Depth d) : pos(p) { - pvNode = pvnode; +MovePicker::MovePicker(const Position& p, bool pv, Move ttm, + const SearchStack& ss, Depth d, EvalInfo* ei) : pos(p) { + pvNode = pv; ttMove = ttm; - mateKiller = (mk == ttm)? MOVE_NONE : mk; - killer1 = k1; - killer2 = k2; + mateKiller = (ss.mateKiller == ttm)? MOVE_NONE : ss.mateKiller; + killer1 = ss.killers[0]; + killer2 = ss.killers[1]; depth = d; movesPicked = 0; numOfMoves = 0; numOfBadCaptures = 0; - dc = p.discovered_check_candidates(p.side_to_move()); + + // With EvalInfo we are able to know how many captures are possible before + // generating them. So avoid generating in case we know are zero. + Color us = pos.side_to_move(); + Color them = opposite_color(us); + bool noCaptures = ei + && (ei->attackedBy[us][0] & pos.pieces_of_color(them)) == 0 + && !ei->mi->specialized_eval_exists() + && (pos.ep_square() == SQ_NONE) + && !pos.has_pawn_on_7th(us); if (p.is_check()) - phaseIndex = EvasionsPhaseIndex; + phaseIndex = EvasionsPhaseIndex; else if (depth > Depth(0)) - phaseIndex = MainSearchPhaseIndex; + phaseIndex = MainSearchPhaseIndex; else if (depth == Depth(0)) - phaseIndex = QsearchWithChecksPhaseIndex; + phaseIndex = (noCaptures ? QsearchNoCapturesPhaseIndex : QsearchWithChecksPhaseIndex); else - phaseIndex = QsearchWithoutChecksPhaseIndex; + phaseIndex = (noCaptures ? NoMovesPhaseIndex : QsearchWithoutChecksPhaseIndex); + dc = p.discovered_check_candidates(us); pinned = p.pinned_pieces(p.side_to_move()); finished = false; @@ -206,22 +219,36 @@ void MovePicker::score_captures() { // Suprisingly, this appears to perform slightly better than SEE based // move ordering. The reason is probably that in a position with a winning // capture, capturing a more valuable (but sufficiently defended) piece - // first usually doesn't hurt. The opponent will have to recapture, and + // first usually doesn't hurt. The opponent will have to recapture, and // the hanging piece will still be hanging (except in the unusual cases // where it is possible to recapture with the hanging piece). Exchanging // big pieces before capturing a hanging piece probably helps to reduce - // the subtree size. Instead of calculating SEE here to filter out - // loosing captures, we delay the filtering in pick_move_from_list() + // the subtree size. + // While scoring captures it moves all captures with negative SEE values + // to the badCaptures[] array. Move m; + int seeValue; for (int i = 0; i < numOfMoves; i++) { m = moves[i].move; - if (move_promotion(m)) - moves[i].score = QueenValueMidgame; + seeValue = pos.see(m); + if (seeValue >= 0) + { + if (move_promotion(m)) + moves[i].score = QueenValueMidgame; + else + moves[i].score = int(pos.midgame_value_of_piece_on(move_to(m))) + -int(pos.type_of_piece_on(move_from(m))); + } else - moves[i].score = int(pos.midgame_value_of_piece_on(move_to(m))) - -int(pos.type_of_piece_on(move_from(m))); + { + // Losing capture, move it to the badCaptures[] array + assert(numOfBadCaptures < 63); + moves[i].score = seeValue; + badCaptures[numOfBadCaptures++] = moves[i]; + moves[i--] = moves[--numOfMoves]; + } } } @@ -265,7 +292,6 @@ void MovePicker::score_evasions() { } else moves[i].score = H.move_ordering_score(pos.piece_on(move_from(m)), m); } - // FIXME try psqt also here } void MovePicker::score_qcaptures() { @@ -283,8 +309,11 @@ void MovePicker::score_qcaptures() { } -/// find_best_index() loops across the moves and returns index of -/// the highest scored one. +/// find_best_index() loops across the moves and returns index of +/// the highest scored one. There is also a second version that +/// lowers the priority of moves that attack the same square, +/// so that if the best move that attack a square fails the next +/// move picked attacks a different square if any, not the same one. int MovePicker::find_best_index() { @@ -299,14 +328,48 @@ int MovePicker::find_best_index() { return bestIndex; } +int MovePicker::find_best_index(Bitboard* squares, int values[]) { + + int hs; + Move m; + Square to; + int bestScore = -10000000, bestIndex = -1; + + for (int i = movesPicked; i < numOfMoves; i++) + { + m = moves[i].move; + to = move_to(m); + + if (!bit_is_set(*squares, to)) + { + // Init at first use + set_bit(squares, to); + values[to] = 0; + } + + hs = moves[i].score - values[to]; + if (hs > bestScore) + { + bestIndex = i; + bestScore = hs; + } + } + + if (bestIndex != -1) + { + // Raise value of the picked square, so next attack + // to the same square will get low priority. + to = move_to(moves[bestIndex].move); + values[to] += 0xB00; + } + return bestIndex; +} + /// MovePicker::pick_move_from_list() picks the move with the biggest score /// from a list of generated moves (moves[] or badCaptures[], depending on /// the current move generation phase). It takes care not to return the /// transposition table move if that has already been serched previously. -/// While picking captures in the PH_GOOD_CAPTURES phase (i.e. while picking -/// non-losing captures in the main search), it moves all captures with -/// negative SEE values to the badCaptures[] array. Move MovePicker::pick_move_from_list() { @@ -322,19 +385,9 @@ Move MovePicker::pick_move_from_list() { { bestIndex = find_best_index(); - if (bestIndex != -1) // Found a possibly good capture + if (bestIndex != -1) // Found a good capture { move = moves[bestIndex].move; - int seeValue = pos.see(move); - if (seeValue < 0) - { - // Losing capture, move it to the badCaptures[] array - assert(numOfBadCaptures < 63); - moves[bestIndex].score = seeValue; - badCaptures[numOfBadCaptures++] = moves[bestIndex]; - moves[bestIndex] = moves[--numOfMoves]; - continue; - } moves[bestIndex] = moves[movesPicked++]; if ( move != ttMove && move != mateKiller @@ -451,8 +504,9 @@ MovePicker::MovegenPhase MovePicker::current_move_type() const { /// MovePicker::init_phase_table() initializes the PhaseTable[], /// MainSearchPhaseIndex, EvasionPhaseIndex, QsearchWithChecksPhaseIndex -/// and QsearchWithoutChecksPhaseIndex variables. It is only called once -/// during program startup, and never again while the program is running. +/// QsearchNoCapturesPhaseIndex, QsearchWithoutChecksPhaseIndex and +/// NoMovesPhaseIndex variables. It is only called once during program +/// startup, and never again while the program is running. void MovePicker::init_phase_table() { @@ -481,8 +535,17 @@ void MovePicker::init_phase_table() { PhaseTable[i++] = PH_QCHECKS; PhaseTable[i++] = PH_STOP; + // Quiescence search with checks only and no captures + QsearchNoCapturesPhaseIndex = i - 1; + PhaseTable[i++] = PH_QCHECKS; + PhaseTable[i++] = PH_STOP; + // Quiescence search without checks QsearchWithoutChecksPhaseIndex = i - 1; PhaseTable[i++] = PH_QCAPTURES; PhaseTable[i++] = PH_STOP; + + // Do not generate any move + NoMovesPhaseIndex = i - 1; + PhaseTable[i++] = PH_STOP; }