X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=ec4272a9e0f9bcb7ebf601515621e34be4e632ba;hp=08e3a997c4d3c63365e24040e1803d298e8b3075;hb=51c3af9dd01951cf23f17c5f7c6cb9f7c32dccdc;hpb=fe523b2d18c0bb4533aad296fd44d504f67f2d4a diff --git a/src/search.cpp b/src/search.cpp index 08e3a997..ec4272a9 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -189,9 +189,6 @@ namespace { // Remaining depth: 1 ply 1.5 ply 2 ply 2.5 ply 3 ply 3.5 ply const Value RazorApprMargins[6] = { Value(0x520), Value(0x300), Value(0x300), Value(0x300), Value(0x300), Value(0x300) }; - // The main transposition table - TranspositionTable TT; - /// Variables initialized by UCI options @@ -302,6 +299,7 @@ namespace { void ponderhit(); void print_current_line(SearchStack ss[], int ply, int threadID); void wait_for_stop_or_ponderhit(); + void init_ss_array(SearchStack ss[]); void idle_loop(int threadID, SplitPoint* waitSp); void init_split_point_stack(); @@ -310,7 +308,9 @@ namespace { bool thread_is_available(int slave, int master); bool idle_thread_exists(int master); bool split(const Position& pos, SearchStack* ss, int ply, - Value *alpha, Value *beta, Value *bestValue, Depth depth, int *moves, + Value *alpha, Value *beta, Value *bestValue, + const Value futilityValue, const Value approximateValue, + Depth depth, int *moves, MovePicker *mp, Bitboard dcCandidates, int master, bool pvNode); void wake_sleeping_threads(); @@ -414,6 +414,7 @@ bool think(const Position& pos, bool infinite, bool ponder, int side_to_move, read_weights(pos.side_to_move()); + // Set the number of active threads int newActiveThreads = get_option_value_int("Threads"); if (newActiveThreads != ActiveThreads) { @@ -447,7 +448,8 @@ bool think(const Position& pos, bool infinite, bool ponder, int side_to_move, if (movesToGo == 1) { MaxSearchTime = myTime / 2; - AbsoluteMaxSearchTime = Min(myTime / 2, myTime - 500); + AbsoluteMaxSearchTime = + (myTime > 3000)? (myTime - 500) : ((myTime * 3) / 4); } else { MaxSearchTime = myTime / Min(movesToGo, 20); AbsoluteMaxSearchTime = Min((4 * myTime) / movesToGo, myTime / 3); @@ -471,10 +473,13 @@ bool think(const Position& pos, bool infinite, bool ponder, int side_to_move, NodesBetweenPolls = Min(MaxNodes, 30000); InfiniteSearch = true; // HACK } + else if (myTime && myTime < 1000) + NodesBetweenPolls = 1000; + else if (myTime && myTime < 5000) + NodesBetweenPolls = 5000; else NodesBetweenPolls = 30000; - // Write information to search log file if (UseLogFile) LogFile << "Searching: " << pos.to_fen() << std::endl @@ -492,9 +497,9 @@ bool think(const Position& pos, bool infinite, bool ponder, int side_to_move, { Value v = id_loop(pos, searchMoves); loseOnTime = ( UseLSNFiltering - && myTime < LSNTime - && myIncrement == 0 - && v < -LSNValue); + && myTime < LSNTime + && myIncrement == 0 + && v < -LSNValue); } else { @@ -627,14 +632,19 @@ namespace { // searchMoves are verified, copied, scored and sorted RootMoveList rml(p, searchMoves); + // Print RootMoveList c'tor startup scoring to the standard output, + // so that we print information also for iteration 1. + std::cout << "info depth " << 1 << "\ninfo depth " << 1 + << " score " << value_to_string(rml.get_move_score(0)) + << " time " << current_search_time() + << " nodes " << nodes_searched() + << " nps " << nps() + << " pv " << rml.get_move(0) << "\n"; + // Initialize TT.new_search(); H.clear(); - for (int i = 0; i < 3; i++) - { - ss[i].init(i); - ss[i].initKillers(); - } + init_ss_array(ss); IterationInfo[1] = IterationInfoType(rml.get_move_score(0), rml.get_move_score(0)); Iteration = 1; @@ -858,8 +868,9 @@ namespace { << " currmovenumber " << i + 1 << std::endl; // Decide search depth for this move + bool moveIsCapture = pos.move_is_capture(move); bool dangerous; - ext = extension(pos, move, true, pos.move_is_capture(move), pos.move_is_check(move), false, false, &dangerous); + ext = extension(pos, move, true, moveIsCapture, pos.move_is_check(move), false, false, &dangerous); newDepth = (Iteration - 2) * OnePly + ext + InitialDepth; // Make the move, and search it @@ -883,15 +894,30 @@ namespace { } else { - value = -search(pos, ss, -alpha, newDepth, 1, true, 0); + if ( newDepth >= 3*OnePly + && i >= MultiPV + LMRPVMoves + && !dangerous + && !moveIsCapture + && !move_is_promotion(move) + && !move_is_castle(move)) + { + ss[0].reduction = OnePly; + value = -search(pos, ss, -alpha, newDepth-OnePly, 1, true, 0); + } else + value = alpha + 1; // Just to trigger next condition + if (value > alpha) { - // Fail high! Set the boolean variable FailHigh to true, and - // re-search the move with a big window. The variable FailHigh is - // used for time managment: We try to avoid aborting the search - // prematurely during a fail high research. - FailHigh = true; - value = -search_pv(pos, ss, -beta, -alpha, newDepth, 1, 0); + value = -search(pos, ss, -alpha, newDepth, 1, true, 0); + if (value > alpha) + { + // Fail high! Set the boolean variable FailHigh to true, and + // re-search the move with a big window. The variable FailHigh is + // used for time managment: We try to avoid aborting the search + // prematurely during a fail high research. + FailHigh = true; + value = -search_pv(pos, ss, -beta, -alpha, newDepth, 1, 0); + } } } @@ -925,6 +951,7 @@ namespace { // Update PV rml.set_move_score(i, value); update_pv(ss, 0); + TT.extract_pv(pos, ss[0].pv, PLY_MAX); rml.set_move_pv(i, ss[0].pv); if (MultiPV == 1) @@ -938,6 +965,8 @@ namespace { // Print search information to the standard output std::cout << "info depth " << Iteration << " score " << value_to_string(value) + << ((value >= beta)? + " lowerbound" : ((value <= alpha)? " upperbound" : "")) << " time " << current_search_time() << " nodes " << nodes_searched() << " nps " << nps() @@ -949,7 +978,10 @@ namespace { std::cout << std::endl; if (UseLogFile) - LogFile << pretty_pv(pos, current_search_time(), Iteration, nodes_searched(), value, ss[0].pv) + LogFile << pretty_pv(pos, current_search_time(), Iteration, nodes_searched(), value, + ((value >= beta)? VALUE_TYPE_LOWER + : ((value <= alpha)? VALUE_TYPE_UPPER : VALUE_TYPE_EXACT)), + ss[0].pv) << std::endl; if (value > alpha) @@ -1018,7 +1050,7 @@ namespace { EvalInfo ei; if (ply >= PLY_MAX - 1) - return evaluate(pos, ei, threadID); + return pos.is_check() ? quick_evaluate(pos) : evaluate(pos, ei, threadID); // Mate distance pruning Value oldAlpha = alpha; @@ -1041,16 +1073,16 @@ namespace { // Initialize a MovePicker object for the current position, and prepare // to search all moves - MovePicker mp = MovePicker(pos, ttMove, depth, H, &ss[ply]); - Move move, movesSearched[256]; int moveCount = 0; Value value, bestValue = -VALUE_INFINITE; - Bitboard dcCandidates = mp.discovered_check_candidates(); Color us = pos.side_to_move(); bool isCheck = pos.is_check(); bool mateThreat = pos.has_mate_threat(opposite_color(us)); + MovePicker mp = MovePicker(pos, ttMove, depth, H, &ss[ply]); + Bitboard dcCandidates = mp.discovered_check_candidates(); + // Loop through all legal moves until no moves remain or a beta cutoff // occurs. while ( alpha < beta @@ -1059,7 +1091,7 @@ namespace { { assert(move_is_ok(move)); - bool singleReply = (isCheck && mp.number_of_moves() == 1); + bool singleReply = (isCheck && mp.number_of_evasions() == 1); bool moveIsCheck = pos.move_is_check(move, dcCandidates); bool moveIsCapture = pos.move_is_capture(move); @@ -1080,7 +1112,7 @@ namespace { { // Try to reduce non-pv search depth by one ply if move seems not problematic, // if the move fails high will be re-searched at full depth. - if ( depth >= 2*OnePly + if ( depth >= 3*OnePly && moveCount >= LMRPVMoves && !dangerous && !moveIsCapture @@ -1146,7 +1178,7 @@ namespace { && idle_thread_exists(threadID) && !AbortSearch && !thread_should_stop(threadID) - && split(pos, ss, ply, &alpha, &beta, &bestValue, depth, + && split(pos, ss, ply, &alpha, &beta, &bestValue, VALUE_NONE, VALUE_NONE, depth, &moveCount, &mp, dcCandidates, threadID, true)) break; } @@ -1208,7 +1240,7 @@ namespace { EvalInfo ei; if (ply >= PLY_MAX - 1) - return evaluate(pos, ei, threadID); + return pos.is_check() ? quick_evaluate(pos) : evaluate(pos, ei, threadID); // Mate distance pruning if (value_mated_in(ply) >= beta) @@ -1243,16 +1275,13 @@ namespace { StateInfo st; pos.do_null_move(st); + int R = (depth >= 5 * OnePly ? 4 : 3); // Null move dynamic reduction - Value nullValue = -search(pos, ss, -(beta-1), depth-4*OnePly, ply+1, false, threadID); + Value nullValue = -search(pos, ss, -(beta-1), depth-R*OnePly, ply+1, false, threadID); pos.undo_null_move(); - if (value_is_mate(nullValue)) - { - /* Do not return unproven mates */ - } - else if (nullValue >= beta) + if (nullValue >= beta) { if (depth < 6 * OnePly) return beta; @@ -1311,6 +1340,10 @@ namespace { bool useFutilityPruning = depth < SelectiveDepth && !isCheck; + // Avoid calling evaluate() if we already have the score in TT + if (tte && (tte->type() & VALUE_TYPE_EVAL)) + futilityValue = value_from_tt(tte->value(), ply) + FutilityMargins[int(depth) - 2]; + // Loop through all legal moves until no moves remain or a beta cutoff // occurs. while ( bestValue < beta @@ -1319,7 +1352,7 @@ namespace { { assert(move_is_ok(move)); - bool singleReply = (isCheck && mp.number_of_moves() == 1); + bool singleReply = (isCheck && mp.number_of_evasions() == 1); bool moveIsCheck = pos.move_is_check(move, dcCandidates); bool moveIsCapture = pos.move_is_capture(move); @@ -1338,7 +1371,8 @@ namespace { { // History pruning. See ok_to_prune() definition if ( moveCount >= 2 + int(depth) - && ok_to_prune(pos, move, ss[ply].threatMove, depth)) + && ok_to_prune(pos, move, ss[ply].threatMove, depth) + && bestValue > value_mated_in(PLY_MAX)) continue; // Value based pruning @@ -1363,7 +1397,7 @@ namespace { // Try to reduce non-pv search depth by one ply if move seems not problematic, // if the move fails high will be re-searched at full depth. - if ( depth >= (ss[ply-1].currentMove == MOVE_NULL ? 3 : 2) * OnePly + if ( depth >= 3*OnePly && moveCount >= LMRNonPVMoves && !dangerous && !moveIsCapture @@ -1405,7 +1439,7 @@ namespace { && idle_thread_exists(threadID) && !AbortSearch && !thread_should_stop(threadID) - && split(pos, ss, ply, &beta, &beta, &bestValue, depth, &moveCount, + && split(pos, ss, ply, &beta, &beta, &bestValue, futilityValue, approximateEval, depth, &moveCount, &mp, dcCandidates, threadID, false)) break; } @@ -1488,7 +1522,7 @@ namespace { if (isCheck) staticValue = -VALUE_INFINITE; - else if (tte && tte->type() == VALUE_TYPE_EVAL) + else if (tte && (tte->type() & VALUE_TYPE_EVAL)) { // Use the cached evaluation score if possible assert(ei.futilityMargin == Value(0)); @@ -1498,8 +1532,8 @@ namespace { else staticValue = evaluate(pos, ei, threadID); - if (ply == PLY_MAX - 1) - return evaluate(pos, ei, threadID); + if (ply >= PLY_MAX - 1) + return pos.is_check() ? quick_evaluate(pos) : evaluate(pos, ei, threadID); // Initialize "stand pat score", and return it immediately if it is // at least beta. @@ -1509,7 +1543,7 @@ namespace { { // Store the score to avoid a future costly evaluation() call if (!isCheck && !tte && ei.futilityMargin == 0) - TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_EVAL, Depth(-127*OnePly), MOVE_NONE); + TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_EV_LO, Depth(-127*OnePly), MOVE_NONE); return bestValue; } @@ -1597,9 +1631,13 @@ namespace { Move m = ss[ply].pv[ply]; if (!pvNode) { + // If bestValue isn't changed it means it is still the static evaluation of + // the node, so keep this info to avoid a future costly evaluation() call. + ValueType type = (bestValue == staticValue && !ei.futilityMargin ? VALUE_TYPE_EV_UP : VALUE_TYPE_UPPER); Depth d = (depth == Depth(0) ? Depth(0) : Depth(-1)); + if (bestValue < beta) - TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_UPPER, d, MOVE_NONE); + TT.store(pos.get_key(), value_to_tt(bestValue, ply), type, d, MOVE_NONE); else TT.store(pos.get_key(), value_to_tt(bestValue, ply), VALUE_TYPE_LOWER, d, m); } @@ -1657,10 +1695,37 @@ namespace { if ( useFutilityPruning && !dangerous && !moveIsCapture - && !move_is_promotion(move) - && moveCount >= 2 + int(sp->depth) - && ok_to_prune(pos, move, ss[sp->ply].threatMove, sp->depth)) - continue; + && !move_is_promotion(move)) + { + // History pruning. See ok_to_prune() definition + if ( moveCount >= 2 + int(sp->depth) + && ok_to_prune(pos, move, ss[sp->ply].threatMove, sp->depth) + && sp->bestValue > value_mated_in(PLY_MAX)) + continue; + + // Value based pruning + if (sp->approximateEval < sp->beta) + { + if (sp->futilityValue == VALUE_NONE) + { + EvalInfo ei; + sp->futilityValue = evaluate(pos, ei, threadID) + + FutilityMargins[int(sp->depth) - 2]; + } + + if (sp->futilityValue < sp->beta) + { + if (sp->futilityValue > sp->bestValue) // Less then 1% of cases + { + lock_grab(&(sp->lock)); + if (sp->futilityValue > sp->bestValue) + sp->bestValue = sp->futilityValue; + lock_release(&(sp->lock)); + } + continue; + } + } + } // Make and search the move. StateInfo st; @@ -1694,21 +1759,24 @@ namespace { break; // New best move? - lock_grab(&(sp->lock)); - if (value > sp->bestValue && !thread_should_stop(threadID)) + if (value > sp->bestValue) // Less then 2% of cases { - sp->bestValue = value; - if (sp->bestValue >= sp->beta) + lock_grab(&(sp->lock)); + if (value > sp->bestValue && !thread_should_stop(threadID)) { - sp_update_pv(sp->parentSstack, ss, sp->ply); - for (int i = 0; i < ActiveThreads; i++) - if (i != threadID && (i == sp->master || sp->slaves[i])) - Threads[i].stop = true; + sp->bestValue = value; + if (sp->bestValue >= sp->beta) + { + sp_update_pv(sp->parentSstack, ss, sp->ply); + for (int i = 0; i < ActiveThreads; i++) + if (i != threadID && (i == sp->master || sp->slaves[i])) + Threads[i].stop = true; - sp->finished = true; - } + sp->finished = true; + } + } + lock_release(&(sp->lock)); } - lock_release(&(sp->lock)); } lock_grab(&(sp->lock)); @@ -1915,15 +1983,15 @@ namespace { bool includeAllMoves = (searchMoves[0] == MOVE_NONE); // Generate all legal moves - int lm_count = generate_legal_moves(pos, mlist); + MoveStack* last = generate_moves(pos, mlist); // Add each move to the moves[] array - for (int i = 0; i < lm_count; i++) + for (MoveStack* cur = mlist; cur != last; cur++) { bool includeMove = includeAllMoves; for (int k = 0; !includeMove && searchMoves[k] != MOVE_NONE; k++) - includeMove = (searchMoves[k] == mlist[i].move); + includeMove = (searchMoves[k] == cur->move); if (!includeMove) continue; @@ -1931,8 +1999,9 @@ namespace { // Find a quick score for the move StateInfo st; SearchStack ss[PLY_MAX_PLUS_2]; + init_ss_array(ss); - moves[count].move = mlist[i].move; + moves[count].move = cur->move; pos.do_move(moves[count].move, st); moves[count].score = -qsearch(pos, ss, -VALUE_INFINITE, VALUE_INFINITE, Depth(0), 1, 0); pos.undo_move(moves[count].move); @@ -2103,7 +2172,9 @@ namespace { // the second move is assumed to be a move from the current position. bool connected_moves(const Position& pos, Move m1, Move m2) { + Square f1, t1, f2, t2; + Piece p; assert(move_is_ok(m1)); assert(move_is_ok(m2)); @@ -2129,31 +2200,32 @@ namespace { return true; // Case 4: The destination square for m2 is attacked by the moving piece in m1 - if (pos.piece_attacks_square(pos.piece_on(t1), t1, t2)) + p = pos.piece_on(t1); + if (bit_is_set(pos.attacks_from(p, t1), t2)) return true; // Case 5: Discovered check, checking piece is the piece moved in m1 - if ( piece_is_slider(pos.piece_on(t1)) + if ( piece_is_slider(p) && bit_is_set(squares_between(t1, pos.king_square(pos.side_to_move())), f2) - && !bit_is_set(squares_between(t2, pos.king_square(pos.side_to_move())), t2)) + && !bit_is_set(squares_between(t1, pos.king_square(pos.side_to_move())), t2)) { Bitboard occ = pos.occupied_squares(); Color us = pos.side_to_move(); Square ksq = pos.king_square(us); clear_bit(&occ, f2); - if (pos.type_of_piece_on(t1) == BISHOP) + if (type_of_piece(p) == BISHOP) { if (bit_is_set(bishop_attacks_bb(ksq, occ), t1)) return true; } - else if (pos.type_of_piece_on(t1) == ROOK) + else if (type_of_piece(p) == ROOK) { if (bit_is_set(rook_attacks_bb(ksq, occ), t1)) return true; } else { - assert(pos.type_of_piece_on(t1) == QUEEN); + assert(type_of_piece(p) == QUEEN); if (bit_is_set(queen_attacks_bb(ksq, occ), t1)) return true; } @@ -2201,25 +2273,29 @@ namespace { assert(m != MOVE_NONE); Depth result = Depth(0); - *dangerous = check || singleReply || mateThreat; + *dangerous = check | singleReply | mateThreat; - if (check) - result += CheckExtension[pvNode]; + if (*dangerous) + { + if (check) + result += CheckExtension[pvNode]; - if (singleReply) - result += SingleReplyExtension[pvNode]; + if (singleReply) + result += SingleReplyExtension[pvNode]; - if (mateThreat) - result += MateThreatExtension[pvNode]; + if (mateThreat) + result += MateThreatExtension[pvNode]; + } if (pos.type_of_piece_on(move_from(m)) == PAWN) { - if (pos.move_is_pawn_push_to_7th(m)) + Color c = pos.side_to_move(); + if (relative_rank(c, move_to(m)) == RANK_7) { result += PawnPushTo7thExtension[pvNode]; *dangerous = true; } - if (pos.move_is_passed_pawn_push(m)) + if (pos.pawn_is_passed(c, move_to(m))) { result += PassedPawnExtension[pvNode]; *dangerous = true; @@ -2376,6 +2452,7 @@ namespace { ss.killers[0] = m; } + // fail_high_ply_1() checks if some thread is currently resolving a fail // high at ply 1 at the node below the first root node. This information // is used for time managment. @@ -2522,6 +2599,18 @@ namespace { } + // init_ss_array() does a fast reset of the first entries of a SearchStack array + + void init_ss_array(SearchStack ss[]) { + + for (int i = 0; i < 3; i++) + { + ss[i].init(i); + ss[i].initKillers(); + } + } + + // wait_for_stop_or_ponderhit() is called when the maximum depth is reached // while the program is pondering. The point is to work around a wrinkle in // the UCI protocol: When pondering, the engine is not allowed to give a @@ -2699,7 +2788,8 @@ namespace { // splitPoint->cpus becomes 0), split() returns true. bool split(const Position& p, SearchStack* sstck, int ply, - Value* alpha, Value* beta, Value* bestValue, Depth depth, int* moves, + Value* alpha, Value* beta, Value* bestValue, const Value futilityValue, + const Value approximateEval, Depth depth, int* moves, MovePicker* mp, Bitboard dcCandidates, int master, bool pvNode) { assert(p.is_ok()); @@ -2739,6 +2829,8 @@ namespace { splitPoint->pvNode = pvNode; splitPoint->dcCandidates = dcCandidates; splitPoint->bestValue = *bestValue; + splitPoint->futilityValue = futilityValue; + splitPoint->approximateEval = approximateEval; splitPoint->master = master; splitPoint->mp = mp; splitPoint->moves = *moves;