X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=22dc401c05df1e7e775af6f1660b85fd7e3a889c;hp=132af364d7f787cddbfff1e61c24d2d42b168fa6;hb=2a0bbb9faa7884b486579e095b7ebc25205f1347;hpb=b50eb6bea866a297cd59eb92b7d552480544ff8d diff --git a/src/search.cpp b/src/search.cpp index 132af364..22dc401c 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -153,7 +153,7 @@ void Search::init() { /// Search::perft() is our utility to verify move generation. All the leaf nodes /// up to the given depth are generated and counted and the sum returned. -size_t Search::perft(Position& pos, Depth depth) { +static size_t perft(Position& pos, Depth depth) { StateInfo st; size_t cnt = 0; @@ -163,12 +163,15 @@ size_t Search::perft(Position& pos, Depth depth) { for (MoveList it(pos); *it; ++it) { pos.do_move(*it, st, ci, pos.move_gives_check(*it, ci)); - cnt += leaf ? MoveList(pos).size() : perft(pos, depth - ONE_PLY); + cnt += leaf ? MoveList(pos).size() : ::perft(pos, depth - ONE_PLY); pos.undo_move(*it); } return cnt; } +size_t Search::perft(Position& pos, Depth depth) { + return depth > ONE_PLY ? ::perft(pos, depth) : MoveList(pos).size(); +} /// Search::think() is the external interface to Stockfish's search, and is /// called by the main thread when the program receives the UCI 'go' command. It @@ -212,7 +215,7 @@ void Search::think() { else DrawValue[WHITE] = DrawValue[BLACK] = VALUE_DRAW; - if (Options["Use Search Log"]) + if (Options["Write Search Log"]) { Log log(Options["Search Log Filename"]); log << "\nSearching: " << RootPos.fen() @@ -228,7 +231,7 @@ void Search::think() { for (size_t i = 0; i < Threads.size(); i++) Threads[i]->maxPly = 0; - Threads.sleepWhileIdle = Options["Use Sleeping Threads"]; + Threads.sleepWhileIdle = Options["Idle Threads Sleep"]; // Set best timer interval to avoid lagging under time pressure. Timer is // used to check for remaining available thinking time. @@ -244,7 +247,7 @@ void Search::think() { Threads.timer->msec = 0; // Stop the timer Threads.sleepWhileIdle = true; // Send idle threads to sleep - if (Options["Use Search Log"]) + if (Options["Write Search Log"]) { Time::point elapsed = Time::now() - SearchTime + 1; @@ -364,6 +367,12 @@ namespace { if (Signals.stop) return; + // When failing high/low give some update (without cluttering + // the UI) before to research. + if ( (bestValue <= alpha || bestValue >= beta) + && Time::now() - SearchTime > 3000) + sync_cout << uci_pv(pos, depth, alpha, beta) << sync_endl; + // In case of failing low/high increase aspiration window and // research, otherwise exit the loop. if (bestValue <= alpha) @@ -382,10 +391,6 @@ namespace { delta += delta / 2; assert(alpha >= -VALUE_INFINITE && beta <= VALUE_INFINITE); - - // Give some update (without cluttering the UI) before to research - if (Time::now() - SearchTime > 3000) - sync_cout << uci_pv(pos, depth, alpha, beta) << sync_endl; } // Sort the PV lines searched so far and update the GUI @@ -399,7 +404,7 @@ namespace { if (skill.enabled() && skill.time_to_pick(depth)) skill.pick_move(); - if (Options["Use Search Log"]) + if (Options["Write Search Log"]) { RootMove& rm = RootMoves[0]; if (skill.best != MOVE_NONE) @@ -482,7 +487,7 @@ namespace { assert(PvNode || (alpha == beta - 1)); assert(depth > DEPTH_ZERO); - Move movesSearched[64]; + Move quietsSearched[64]; StateInfo st; const TTEntry *tte; SplitPoint* splitPoint; @@ -493,11 +498,11 @@ namespace { Value eval, nullValue, futilityValue; bool inCheck, givesCheck, pvMove, singularExtensionNode; bool captureOrPromotion, dangerous, doFullDepthSearch; - int moveCount, playedMoveCount; + int moveCount, quietCount; // Step 1. Initialize node Thread* thisThread = pos.this_thread(); - moveCount = playedMoveCount = 0; + moveCount = quietCount = 0; inCheck = pos.checkers(); if (SpNode) @@ -512,7 +517,7 @@ namespace { assert(splitPoint->bestValue > -VALUE_INFINITE && splitPoint->moveCount > 0); - goto split_point_start; + goto moves_loop; } bestValue = -VALUE_INFINITE; @@ -581,7 +586,10 @@ namespace { // Step 5. Evaluate the position statically and update parent's gain statistics if (inCheck) + { ss->staticEval = ss->evalMargin = eval = VALUE_NONE; + goto moves_loop; + } else if (tte) { @@ -605,10 +613,10 @@ namespace { // Update gain for the parent non-capture move given the static position // evaluation before and after the move. - if ( (move = (ss-1)->currentMove) != MOVE_NULL - && (ss-1)->staticEval != VALUE_NONE + if ( !pos.captured_piece_type() && ss->staticEval != VALUE_NONE - && !pos.captured_piece_type() + && (ss-1)->staticEval != VALUE_NONE + && (move = (ss-1)->currentMove) != MOVE_NULL && type_of(move) == NORMAL) { Square to = to_sq(move); @@ -618,7 +626,6 @@ namespace { // Step 6. Razoring (is omitted in PV nodes) if ( !PvNode && depth < 4 * ONE_PLY - && !inCheck && eval + razor_margin(depth) < beta && ttMove == MOVE_NONE && abs(beta) < VALUE_MATE_IN_MAX_PLY @@ -638,7 +645,6 @@ namespace { if ( !PvNode && !ss->skipNullMove && depth < 4 * ONE_PLY - && !inCheck && eval - futility_margin(depth, (ss-1)->futilityMoveCount) >= beta && abs(beta) < VALUE_MATE_IN_MAX_PLY && abs(eval) < VALUE_KNOWN_WIN @@ -649,7 +655,6 @@ namespace { if ( !PvNode && !ss->skipNullMove && depth > ONE_PLY - && !inCheck && eval >= beta && abs(beta) < VALUE_MATE_IN_MAX_PLY && pos.non_pawn_material(pos.side_to_move())) @@ -711,7 +716,6 @@ namespace { // prune the previous move. if ( !PvNode && depth >= 5 * ONE_PLY - && !inCheck && !ss->skipNullMove && abs(beta) < VALUE_MATE_IN_MAX_PLY) { @@ -740,7 +744,7 @@ namespace { // Step 10. Internal iterative deepening if ( depth >= (PvNode ? 5 * ONE_PLY : 8 * ONE_PLY) && ttMove == MOVE_NONE - && (PvNode || (!inCheck && ss->staticEval + Value(256) >= beta))) + && (PvNode || ss->staticEval + Value(256) >= beta)) { Depth d = depth - 2 * ONE_PLY - (PvNode ? DEPTH_ZERO : depth / 4); @@ -752,7 +756,7 @@ namespace { ttMove = tte ? tte->move() : MOVE_NONE; } -split_point_start: // At split points actual search starts from here +moves_loop: // When in check and at SpNode search starts from here Square prevMoveSq = to_sq((ss-1)->currentMove); Move countermoves[] = { Countermoves[pos.piece_on(prevMoveSq)][prevMoveSq].first, @@ -811,12 +815,7 @@ split_point_start: // At split points actual search starts from here givesCheck = pos.move_gives_check(move, ci); dangerous = givesCheck || pos.is_passed_pawn_push(move) - || type_of(move) == CASTLE - || ( captureOrPromotion // Entering a pawn endgame? - && type_of(pos.piece_on(to_sq(move))) != PAWN - && type_of(move) == NORMAL - && ( pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) - - PieceValue[MG][pos.piece_on(to_sq(move))] == VALUE_ZERO)); + || type_of(move) == CASTLE; // Step 12. Extend checks and, in PV nodes, also dangerous moves if (PvNode && dangerous) @@ -917,8 +916,8 @@ split_point_start: // At split points actual search starts from here pvMove = PvNode && moveCount == 1; ss->currentMove = move; - if (!SpNode && !captureOrPromotion && playedMoveCount < 64) - movesSearched[playedMoveCount++] = move; + if (!SpNode && !captureOrPromotion && quietCount < 64) + quietsSearched[quietCount++] = move; // Step 14. Make the move pos.do_move(move, st, ci, givesCheck); @@ -1069,43 +1068,37 @@ split_point_start: // At split points actual search starts from here // If we have pruned all the moves without searching return a fail-low score if (bestValue == -VALUE_INFINITE) - { - assert(!playedMoveCount); - bestValue = alpha; - } - if (bestValue >= beta) // Failed high + TT.store(posKey, value_to_tt(bestValue, ss->ply), + bestValue >= beta ? BOUND_LOWER : + PvNode && bestMove ? BOUND_EXACT : BOUND_UPPER, + depth, bestMove, ss->staticEval, ss->evalMargin); + + // Quiet best move: update killers, history and countermoves + if ( bestValue >= beta + && !pos.is_capture_or_promotion(bestMove) + && !inCheck) { - TT.store(posKey, value_to_tt(bestValue, ss->ply), BOUND_LOWER, depth, - bestMove, ss->staticEval, ss->evalMargin); - - if (!pos.is_capture_or_promotion(bestMove) && !inCheck) + if (ss->killers[0] != bestMove) { - if (bestMove != ss->killers[0]) - { - ss->killers[1] = ss->killers[0]; - ss->killers[0] = bestMove; - } - - // Increase history value of the cut-off move - Value bonus = Value(int(depth) * int(depth)); - History.update(pos.piece_moved(bestMove), to_sq(bestMove), bonus); - if (is_ok((ss-1)->currentMove)) - Countermoves.update(pos.piece_on(prevMoveSq), prevMoveSq, bestMove); + ss->killers[1] = ss->killers[0]; + ss->killers[0] = bestMove; + } - // Decrease history of all the other played non-capture moves - for (int i = 0; i < playedMoveCount - 1; i++) - { - Move m = movesSearched[i]; - History.update(pos.piece_moved(m), to_sq(m), -bonus); - } + // Increase history value of the cut-off move and decrease all the other + // played non-capture moves. + Value bonus = Value(int(depth) * int(depth)); + History.update(pos.piece_moved(bestMove), to_sq(bestMove), bonus); + for (int i = 0; i < quietCount - 1; i++) + { + Move m = quietsSearched[i]; + History.update(pos.piece_moved(m), to_sq(m), -bonus); } + + if (is_ok((ss-1)->currentMove)) + Countermoves.update(pos.piece_on(prevMoveSq), prevMoveSq, bestMove); } - else // Failed low or PV search - TT.store(posKey, value_to_tt(bestValue, ss->ply), - PvNode && bestMove != MOVE_NONE ? BOUND_EXACT : BOUND_UPPER, - depth, bestMove, ss->staticEval, ss->evalMargin); assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE); @@ -1153,8 +1146,7 @@ split_point_start: // At split points actual search starts from here ttDepth = InCheck || depth >= DEPTH_QS_CHECKS ? DEPTH_QS_CHECKS : DEPTH_QS_NO_CHECKS; - // Transposition table lookup. At PV nodes, we don't use the TT for - // pruning, but only for move ordering. + // Transposition table lookup posKey = pos.key(); tte = TT.probe(posKey); ttMove = tte ? tte->move() : MOVE_NONE;