From: Marco Costalba Date: Sat, 25 Oct 2008 14:28:24 +0000 (+0100) Subject: Restore original movepick modulo space inflation X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=f8bc38a00650c5f4c71aec6f6d5503c7ae4c17a3 Restore original movepick modulo space inflation We have a regression somewhere here so restart from zero and proceed one change at a time. With this modification we have the same strenght of "Introduce Stockfish" patch that is our strongest to date. Signed-off-by: Marco Costalba --- diff --git a/src/movepick.cpp b/src/movepick.cpp index e1f8e4e7..6525c750 100644 --- a/src/movepick.cpp +++ b/src/movepick.cpp @@ -7,12 +7,12 @@ it under the terms of the GNU General Public License as published by 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 GNU General Public License for more details. - + You should have received a copy of the GNU General Public License along with this program. If not, see . */ @@ -61,8 +61,9 @@ 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) { +MovePicker::MovePicker(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; @@ -111,13 +112,16 @@ Move MovePicker::get_next_move() { // Next phase phaseIndex++; switch (PhaseTable[phaseIndex]) { - case PH_TT_MOVE: if (ttMove != MOVE_NONE) { assert(move_is_ok(ttMove)); - if (generate_move_if_legal(pos, ttMove, pinned) != MOVE_NONE) - return ttMove; + Move m = generate_move_if_legal(*pos, ttMove, pinned); + if (m != MOVE_NONE) + { + assert(m == ttMove); + return m; + } } break; @@ -125,13 +129,17 @@ Move MovePicker::get_next_move() { if (mateKiller != MOVE_NONE) { assert(move_is_ok(mateKiller)); - if (generate_move_if_legal(pos, mateKiller, pinned) != MOVE_NONE) - return mateKiller; - } - break; - - case PH_GOOD_CAPTURES: - numOfMoves = generate_captures(pos, moves); + Move m = generate_move_if_legal(*pos, mateKiller, pinned); + if (m != MOVE_NONE) + { + assert(m == mateKiller); + return m; + } + } + break; + + case PH_GOOD_CAPTURES: + numOfMoves = generate_captures(*pos, moves); score_captures(); movesPicked = 0; break; @@ -141,26 +149,26 @@ 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); + 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; @@ -173,7 +181,6 @@ Move MovePicker::get_next_move() { } } assert(false); - return MOVE_NONE; } @@ -183,27 +190,30 @@ Move MovePicker::get_next_move() { 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; + Move m; - lock_release(&lock); - return m; + lock_grab(&lock); + if (finished) + { + lock_release(&lock); + return MOVE_NONE; + } + m = get_next_move(); + if (m == MOVE_NONE) + finished = true; + + lock_release(&lock); + return m; } + /// MovePicker::score_captures(), MovePicker::score_noncaptures(), /// MovePicker::score_evasions() and MovePicker::score_qcaptures() assign a /// numerical move ordering score to each move in a move list. The moves /// with highest scores will be picked first by pick_move_from_list(). void MovePicker::score_captures() { - // Winning and equal captures in the main search are ordered by MVV. + // Winning and equal captures in the main search are ordered by MVV/LVA. // 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 @@ -214,11 +224,16 @@ void MovePicker::score_captures() { // the subtree size. for (int i = 0; i < numOfMoves; i++) { - Move m = moves[i].move; - moves[i].score = pos.see(m); - if (moves[i].score >= 0) - moves[i].score = move_promotion(m) ? QueenValueMidgame - : pos.midgame_value_of_piece_on(move_to(m)); + 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; } } @@ -232,13 +247,7 @@ void MovePicker::score_noncaptures() { else if (m == killer2) moves[i].score = HistoryMax + 1; else - moves[i].score = H.move_ordering_score(pos.piece_on(move_from(m)), m); - - // Ensure moves in history are always sorted as first - if (moves[i].score > 0) - moves[i].score += 1000; - - moves[i].score += pos.mg_pst_delta(moves[i].move); + moves[i].score = H.move_ordering_score(pos->piece_on(move_from(m)), m); } } @@ -249,47 +258,31 @@ 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))) { - moves[i].score = pos.see(m); - if (moves[i].score >= 0) - moves[i].score += HistoryMax; - } - else - moves[i].score = H.move_ordering_score(pos.piece_on(move_from(m)), 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); } // FIXME try psqt also here } void MovePicker::score_qcaptures() { - // Use MVV ordering + // Use MVV/LVA ordering for (int i = 0; i < numOfMoves; i++) { Move m = moves[i].move; - moves[i].score = move_promotion(m) ? QueenValueMidgame - : pos.midgame_value_of_piece_on(move_to(m)); + 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; } } -/// 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 @@ -300,17 +293,18 @@ int MovePicker::find_best_index() { 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) { - int bestScore = -10000000; + bestScore = -10000000; bestIndex = -1; for (int i = movesPicked; i < numOfMoves; i++) { @@ -320,66 +314,87 @@ Move MovePicker::pick_move_from_list() { assert(numOfBadCaptures < 63); badCaptures[numOfBadCaptures++] = moves[i]; moves[i--] = moves[--numOfMoves]; - } - else if (moves[i].score > bestScore) - { - bestIndex = i; - bestScore = moves[i].score; - } + } + else if (moves[i].score > bestScore) + { + bestIndex = i; + bestScore = moves[i].score; + } } if (bestIndex != -1) // Found a good capture { - move = moves[bestIndex].move; + move = moves[bestIndex].move; moves[bestIndex] = moves[movesPicked++]; if ( move != ttMove && move != mateKiller - && pos.move_is_legal(move, pinned)) + && pos->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. - bestIndex = (movesPicked < 12 || pvNode ? find_best_index() : movesPicked); + 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; if (bestIndex != -1) { - move = moves[bestIndex].move; + move = moves[bestIndex].move; moves[bestIndex] = moves[movesPicked++]; if ( move != ttMove && move != mateKiller - && pos.move_is_legal(move, pinned)) + && pos->move_is_legal(move, pinned)) return move; - } - } - break; + } + } + break; case PH_EVASIONS: - assert(pos.is_check()); + assert(pos->is_check()); assert(movesPicked >= 0); + while (movesPicked < numOfMoves) { - bestIndex = find_best_index(); + bestScore = -10000000; + bestIndex = -1; + for (int i = movesPicked; i < numOfMoves; i++) + if(moves[i].score > bestScore) + { + bestIndex = i; + bestScore = moves[i].score; + } if (bestIndex != -1) { - move = moves[bestIndex].move; + move = moves[bestIndex].move; moves[bestIndex] = moves[movesPicked++]; return move; } - } - break; + } + 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 @@ -388,38 +403,51 @@ Move MovePicker::pick_move_from_list() { move = badCaptures[badCapturesPicked++].move; if ( move != ttMove && move != mateKiller - && pos.move_is_legal(move, pinned)) + && pos->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) { - // FIXME makes sens to score qcaps? - bestIndex = (movesPicked < 4 ? find_best_index() : movesPicked); + 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; if (bestIndex != -1) { - move = moves[bestIndex].move; + move = moves[bestIndex].move; moves[bestIndex] = moves[movesPicked++]; - if (move != ttMove && pos.move_is_legal(move, pinned)) + // 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)) 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 while (movesPicked < numOfMoves) { - move = moves[movesPicked++].move; - if (move != ttMove && pos.move_is_legal(move, pinned)) + 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)) return move; } break; @@ -430,19 +458,14 @@ 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 +/// and QsearchWithoutChecksPhaseIndex variables. It is only called once /// during program startup, and never again while the program is running. void MovePicker::init_phase_table() { diff --git a/src/movepick.h b/src/movepick.h index a835346d..cbb69a01 100644 --- a/src/movepick.h +++ b/src/movepick.h @@ -2,12 +2,12 @@ Stockfish, a UCI chess playing engine derived from Glaurung 2.1 Copyright (C) 2004-2008 Tord Romstad (Glaurung author) Copyright (C) 2008 Marco Costalba - + Stockfish is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by 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 @@ -60,7 +60,8 @@ public: PH_STOP }; - MovePicker(const Position& p, bool pvnode, Move ttm, Move mk, Move k1, Move k2, Depth d); + MovePicker(Position &p, bool pvnode, Move ttm, Move mk, Move k1, Move k2, + Depth dpth); Move get_next_move(); Move get_next_move(Lock &lock); int number_of_moves() const; @@ -76,9 +77,8 @@ private: void score_evasions(); void score_qcaptures(); Move pick_move_from_list(); - int find_best_index(); - const Position& pos; + Position *pos; Move ttMove, mateKiller, killer1, killer2; Bitboard pinned, dc; MoveStack moves[256], badCaptures[64]; @@ -101,6 +101,7 @@ private: /// a single reply to check. inline int MovePicker::number_of_moves() const { + return numOfMoves; }