X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovepick.cpp;h=c71572e7cf86bead8aa853dd16db512ab329e55d;hp=6525c7506b8b180cc9f36574c6cc22452c2d96a4;hb=d087b0a34a6aaa0fc31d2fa256b02861d0351256;hpb=f8bc38a00650c5f4c71aec6f6d5503c7ae4c17a3 diff --git a/src/movepick.cpp b/src/movepick.cpp index 6525c750..c71572e7 100644 --- a/src/movepick.cpp +++ b/src/movepick.cpp @@ -8,6 +8,7 @@ the Free Software Foundation, either version 3 of the License, or (at your option) any later version. + Stockfish is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the @@ -39,7 +40,7 @@ namespace { /// Variables - MovePicker::MovegenPhase PhaseTable[32]; + MovePicker::MovegenPhase PhaseTable[32]; int MainSearchPhaseIndex; int EvasionsPhaseIndex; int QsearchWithChecksPhaseIndex; @@ -61,9 +62,8 @@ namespace { /// search captures, promotions and some checks) and about how important good /// move ordering is at the current node. -MovePicker::MovePicker(Position& p, bool pvnode, Move ttm, Move mk, - Move k1, Move k2, Depth d) { - pos = &p; +MovePicker::MovePicker(const Position& p, bool pvnode, Move ttm, Move mk, + Move k1, Move k2, Depth d) : pos(p) { pvNode = pvnode; ttMove = ttm; mateKiller = (mk == ttm)? MOVE_NONE : mk; @@ -112,16 +112,13 @@ Move MovePicker::get_next_move() { // Next phase phaseIndex++; switch (PhaseTable[phaseIndex]) { + case PH_TT_MOVE: if (ttMove != MOVE_NONE) { assert(move_is_ok(ttMove)); - Move m = generate_move_if_legal(*pos, ttMove, pinned); - if (m != MOVE_NONE) - { - assert(m == ttMove); - return m; - } + if (move_is_legal(pos, ttMove, pinned)) + return ttMove; } break; @@ -129,17 +126,13 @@ Move MovePicker::get_next_move() { if (mateKiller != MOVE_NONE) { assert(move_is_ok(mateKiller)); - Move m = generate_move_if_legal(*pos, mateKiller, pinned); - if (m != MOVE_NONE) - { - assert(m == mateKiller); - return m; - } + if (move_is_legal(pos, mateKiller, pinned)) + return mateKiller; } break; case PH_GOOD_CAPTURES: - numOfMoves = generate_captures(*pos, moves); + numOfMoves = generate_captures(pos, moves); score_captures(); movesPicked = 0; break; @@ -149,26 +142,26 @@ Move MovePicker::get_next_move() { break; case PH_NONCAPTURES: - numOfMoves = generate_noncaptures(*pos, moves); + numOfMoves = generate_noncaptures(pos, moves); score_noncaptures(); movesPicked = 0; break; case PH_EVASIONS: - assert(pos->is_check()); - numOfMoves = generate_evasions(*pos, moves); + assert(pos.is_check()); + numOfMoves = generate_evasions(pos, moves); score_evasions(); movesPicked = 0; break; - case PH_QCAPTURES: - numOfMoves = generate_captures(*pos, moves); + case PH_QCAPTURES: + numOfMoves = generate_captures(pos, moves); score_qcaptures(); movesPicked = 0; break; case PH_QCHECKS: - numOfMoves = generate_checks(*pos, moves, dc); + numOfMoves = generate_checks(pos, moves, dc); movesPicked = 0; break; @@ -180,8 +173,6 @@ Move MovePicker::get_next_move() { return MOVE_NONE; } } - assert(false); - return MOVE_NONE; } @@ -190,19 +181,17 @@ Move MovePicker::get_next_move() { Move MovePicker::get_next_move(Lock &lock) { - Move m; - lock_grab(&lock); if (finished) { lock_release(&lock); return MOVE_NONE; } - m = get_next_move(); + Move m = get_next_move(); if (m == MOVE_NONE) finished = true; - lock_release(&lock); + lock_release(&lock); return m; } @@ -217,37 +206,48 @@ 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 + // 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. + // the subtree size. Instead of calculating SEE here to filter out + // loosing captures, we delay the filtering in pick_move_from_list() + Move m; + for (int i = 0; i < numOfMoves; i++) { - int seeValue = pos->see(moves[i].move); - if (seeValue >= 0) - { - if (move_promotion(moves[i].move)) - moves[i].score = QueenValueMidgame; - else - moves[i].score = int(pos->midgame_value_of_piece_on(move_to(moves[i].move))) - -int(pos->type_of_piece_on(move_from(moves[i].move))); - } else - moves[i].score = seeValue; + m = moves[i].move; + 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))); } } void MovePicker::score_noncaptures() { + // First score by history, when no history is available then use + // piece/square tables values. This seems to be better then a + // random choice when we don't have an history for any move. + Move m; + int hs; for (int i = 0; i < numOfMoves; i++) { - Move m = moves[i].move; + m = moves[i].move; + if (m == killer1) - moves[i].score = HistoryMax + 2; + hs = HistoryMax + 2; else if (m == killer2) - moves[i].score = HistoryMax + 1; + hs = HistoryMax + 1; else - moves[i].score = H.move_ordering_score(pos->piece_on(move_from(m)), m); + hs = H.move_ordering_score(pos.piece_on(move_from(m)), m); + + // Ensure moves in history are always sorted as first + if (hs > 0) + hs += 1000; + + moves[i].score = hs + pos.mg_pst_delta(m); } } @@ -258,12 +258,12 @@ void MovePicker::score_evasions() { Move m = moves[i].move; if (m == ttMove) moves[i].score = 2*HistoryMax; - else if(!pos->square_is_empty(move_to(m))) + else if (!pos.square_is_empty(move_to(m))) { - int seeScore = pos->see(m); + int seeScore = pos.see(m); moves[i].score = (seeScore >= 0)? seeScore + HistoryMax : seeScore; } else - moves[i].score = H.move_ordering_score(pos->piece_on(move_from(m)), m); + moves[i].score = H.move_ordering_score(pos.piece_on(move_from(m)), m); } // FIXME try psqt also here } @@ -277,12 +277,29 @@ void MovePicker::score_qcaptures() { if (move_promotion(m)) moves[i].score = QueenValueMidgame; else - moves[i].score = int(pos->midgame_value_of_piece_on(move_to(m))) - -int(pos->midgame_value_of_piece_on(move_to(m))) / 64; + moves[i].score = int(pos.midgame_value_of_piece_on(move_to(m))) + -int(pos.type_of_piece_on(move_from(m))); } } +/// find_best_index() loops across the moves and returns index of +/// the highest scored one. + +int MovePicker::find_best_index() { + + int bestScore = -10000000, bestIndex = -1; + + for (int i = movesPicked; i < numOfMoves; i++) + if (moves[i].score > bestScore) + { + bestIndex = i; + bestScore = moves[i].score; + } + 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 @@ -293,69 +310,51 @@ void MovePicker::score_qcaptures() { Move MovePicker::pick_move_from_list() { - int bestScore = -10000000; int bestIndex; Move move; switch (PhaseTable[phaseIndex]) { case PH_GOOD_CAPTURES: - assert(!pos->is_check()); + assert(!pos.is_check()); assert(movesPicked >= 0); while (movesPicked < numOfMoves) { - bestScore = -10000000; - bestIndex = -1; - for (int i = movesPicked; i < numOfMoves; i++) + bestIndex = find_best_index(); + + if (bestIndex != -1) // Found a possibly good capture { - if (moves[i].score < 0) + move = moves[bestIndex].move; + int seeValue = pos.see(move); + if (seeValue < 0) { // Losing capture, move it to the badCaptures[] array assert(numOfBadCaptures < 63); - badCaptures[numOfBadCaptures++] = moves[i]; - moves[i--] = moves[--numOfMoves]; - } - else if (moves[i].score > bestScore) - { - bestIndex = i; - bestScore = moves[i].score; + moves[bestIndex].score = seeValue; + badCaptures[numOfBadCaptures++] = moves[bestIndex]; + moves[bestIndex] = moves[--numOfMoves]; + continue; } - } - if (bestIndex != -1) // Found a good capture - { - move = moves[bestIndex].move; moves[bestIndex] = moves[movesPicked++]; if ( move != ttMove && move != mateKiller - && pos->move_is_legal(move, pinned)) + && pos.pl_move_is_legal(move, pinned)) return move; } } break; case PH_NONCAPTURES: - assert(!pos->is_check()); + assert(!pos.is_check()); assert(movesPicked >= 0); while (movesPicked < numOfMoves) { - bestScore = -10000000; - // If this is a PV node or we have only picked a few moves, scan // the entire move list for the best move. If many moves have already // been searched and it is not a PV node, we are probably failing low // anyway, so we just pick the first move from the list. - if (pvNode || movesPicked < 12) - { - bestIndex = -1; - for (int i = movesPicked; i < numOfMoves; i++) - if (moves[i].score > bestScore) - { - bestIndex = i; - bestScore = moves[i].score; - } - } else - bestIndex = movesPicked; + bestIndex = (pvNode || movesPicked < 12) ? find_best_index() : movesPicked; if (bestIndex != -1) { @@ -363,26 +362,19 @@ Move MovePicker::pick_move_from_list() { moves[bestIndex] = moves[movesPicked++]; if ( move != ttMove && move != mateKiller - && pos->move_is_legal(move, pinned)) + && pos.pl_move_is_legal(move, pinned)) return move; } } break; case PH_EVASIONS: - assert(pos->is_check()); + assert(pos.is_check()); assert(movesPicked >= 0); while (movesPicked < numOfMoves) { - bestScore = -10000000; - bestIndex = -1; - for (int i = movesPicked; i < numOfMoves; i++) - if(moves[i].score > bestScore) - { - bestIndex = i; - bestScore = moves[i].score; - } + bestIndex = find_best_index(); if (bestIndex != -1) { @@ -394,7 +386,7 @@ Move MovePicker::pick_move_from_list() { break; case PH_BAD_CAPTURES: - assert(!pos->is_check()); + assert(!pos.is_check()); assert(badCapturesPicked >= 0); // It's probably a good idea to use SEE move ordering here, instead // of just picking the first move. FIXME @@ -403,28 +395,17 @@ Move MovePicker::pick_move_from_list() { move = badCaptures[badCapturesPicked++].move; if ( move != ttMove && move != mateKiller - && pos->move_is_legal(move, pinned)) + && pos.pl_move_is_legal(move, pinned)) return move; } break; case PH_QCAPTURES: - assert(!pos->is_check()); + assert(!pos.is_check()); assert(movesPicked >= 0); while (movesPicked < numOfMoves) { - bestScore = -10000000; - if (movesPicked < 4) - { - bestIndex = -1; - for (int i = movesPicked; i < numOfMoves; i++) - if(moves[i].score > bestScore) - { - bestIndex = i; - bestScore = moves[i].score; - } - } else - bestIndex = movesPicked; + bestIndex = (movesPicked < 4 ? find_best_index() : movesPicked); if (bestIndex != -1) { @@ -432,14 +413,14 @@ Move MovePicker::pick_move_from_list() { moves[bestIndex] = moves[movesPicked++]; // Remember to change the line below if we decide to hash the qsearch! // Maybe also postpone the legality check until after futility pruning? - if (/* move != ttMove && */ pos->move_is_legal(move, pinned)) + if (/* move != ttMove && */ pos.pl_move_is_legal(move, pinned)) return move; } } break; case PH_QCHECKS: - assert(!pos->is_check()); + assert(!pos.is_check()); assert(movesPicked >= 0); // Perhaps we should do something better than just picking the first // move here? FIXME @@ -447,7 +428,7 @@ Move MovePicker::pick_move_from_list() { { move = moves[movesPicked++].move; // Remember to change the line below if we decide to hash the qsearch! - if (/* move != ttMove && */ pos->move_is_legal(move, pinned)) + if (/* move != ttMove && */ pos.pl_move_is_legal(move, pinned)) return move; } break; @@ -458,11 +439,16 @@ Move MovePicker::pick_move_from_list() { return MOVE_NONE; } + +/// MovePicker::current_move_type() returns the type of the just +/// picked next move. It can be used in search to further differentiate +/// according to the current move type: capture, non capture, escape, etc. MovePicker::MovegenPhase MovePicker::current_move_type() const { return PhaseTable[phaseIndex]; } + /// MovePicker::init_phase_table() initializes the PhaseTable[], /// MainSearchPhaseIndex, EvasionPhaseIndex, QsearchWithChecksPhaseIndex /// and QsearchWithoutChecksPhaseIndex variables. It is only called once