X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=dd9e45b92e33b3ad606b6c10a40294fa77349058;hp=d8e60a129317f90acda38e5f6f1ae6b5c6b090bf;hb=cf486cf229b9877afd8120830bece47d93c7e8d0;hpb=af3dd21e9053feaf66ad884fae0a014d85c700f2 diff --git a/src/search.cpp b/src/search.cpp index d8e60a12..dd9e45b9 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -139,7 +139,7 @@ namespace { // Use internal iterative deepening? const bool UseIIDAtPVNodes = true; - const bool UseIIDAtNonPVNodes = false; + const bool UseIIDAtNonPVNodes = true; // Internal iterative deepening margin. At Non-PV moves, when // UseIIDAtNonPVNodes is true, we do an internal iterative deepening @@ -173,19 +173,15 @@ namespace { // If the TT move is at least SingleReplyMargin better then the // remaining ones we will extend it. - const Value SingleReplyMargin = Value(0x64); + const Value SingleReplyMargin = Value(0x20); // Margins for futility pruning in the quiescence search, and at frontier // and near frontier nodes. const Value FutilityMarginQS = Value(0x80); // Each move futility margin is decreased - const Value IncrementalFutilityMargin = Value(0x4); + const Value IncrementalFutilityMargin = Value(0x8); - // Remaining depth: 1 ply 1.5 ply 2 ply 2.5 ply 3 ply 3.5 ply - const Value FutilityMargins[12] = { Value(0x100), Value(0x120), Value(0x200), Value(0x220), Value(0x250), Value(0x270), - // 4 ply 4.5 ply 5 ply 5.5 ply 6 ply 6.5 ply - Value(0x2A0), Value(0x2C0), Value(0x340), Value(0x360), Value(0x3A0), Value(0x3C0) }; // Razoring const Depth RazorDepth = 4*OnePly; @@ -292,7 +288,7 @@ namespace { bool move_is_killer(Move m, const SearchStack& ss); Depth extension(const Position& pos, Move m, bool pvNode, bool capture, bool check, bool singleReply, bool mateThreat, bool* dangerous); bool ok_to_do_nullmove(const Position& pos); - bool ok_to_prune(const Position& pos, Move m, Move threat, Depth d); + bool ok_to_prune(const Position& pos, Move m, Move threat); bool ok_to_use_TT(const TTEntry* tte, Depth depth, Value beta, int ply); void update_history(const Position& pos, Move m, Depth depth, Move movesSearched[], int moveCount); void update_killers(Move m, SearchStack& ss); @@ -377,7 +373,7 @@ bool think(const Position& pos, bool infinite, bool ponder, int side_to_move, { Move bookMove; if (get_option_value_string("Book File") != OpeningBook.file_name()) - OpeningBook.open("book.bin"); + OpeningBook.open(get_option_value_string("Book File")); bookMove = OpeningBook.get_move(pos); if (bookMove != MOVE_NONE) @@ -406,13 +402,13 @@ bool think(const Position& pos, bool infinite, bool ponder, int side_to_move, Problem = false; ExactMaxTime = maxTime; + if (button_was_pressed("New Game")) + loseOnTime = false; // reset at the beginning of a new game + // Read UCI option values TT.set_size(get_option_value_int("Hash")); if (button_was_pressed("Clear Hash")) - { TT.clear(); - loseOnTime = false; // reset at the beginning of a new game - } bool PonderingEnabled = get_option_value_bool("Ponder"); MultiPV = get_option_value_int("MultiPV"); @@ -681,6 +677,14 @@ namespace { // searchMoves are verified, copied, scored and sorted RootMoveList rml(p, searchMoves); + if (rml.move_count() == 0) + { + if (PonderSearch) + wait_for_stop_or_ponderhit(); + + return pos.is_check()? -VALUE_MATE : VALUE_DRAW; + } + // 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 @@ -1138,9 +1142,6 @@ namespace { search_pv(pos, ss, alpha, beta, depth-2*OnePly, ply, threadID); ttMove = ss[ply].pv[ply]; tte = TT.retrieve(pos.get_key()); - - // If tte->move() != MOVE_NONE then it equals ttMove - assert(!(tte && tte->move()) || tte->move() == ttMove); } // Initialize a MovePicker object for the current position, and prepare @@ -1359,7 +1360,7 @@ namespace { if (tte && ok_to_use_TT(tte, depth, beta, ply)) { - ss[ply].currentMove = ttMove; // can be MOVE_NONE + ss[ply].currentMove = ttMove; // Can be MOVE_NONE return value_from_tt(tte->value(), ply); } @@ -1431,7 +1432,7 @@ namespace { // Go with internal iterative deepening if we don't have a TT move if (UseIIDAtNonPVNodes && ttMove == MOVE_NONE && depth >= 8*OnePly && - evaluate(pos, ei, threadID) >= beta - IIDMargin) + !isCheck && evaluate(pos, ei, threadID) >= beta - IIDMargin) { search(pos, ss, beta, Min(depth/2, depth-2*OnePly), ply, false, threadID); ttMove = ss[ply].pv[ply]; @@ -1445,18 +1446,13 @@ namespace { futilityValue = VALUE_NONE; useFutilityPruning = depth < SelectiveDepth && !isCheck; + // Calculate depth dependant futility pruning parameters + const int FutilityMoveCountMargin = 3 + (1 << (3 * int(depth) / 8)); + const int FutilityValueMargin = 112 * bitScanReverse32(int(depth) * int(depth) / 2); + // 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]; - - // Move count pruning limit - const int MCLimit = 3 + (1 << (3*int(depth)/8)); - - /* - for (int d = 2; d < 16; d++) - std::cout << d << " -> " << 56*(0+2*bitScanReverse32(1 * int(d) * int(d) / 2)) << std::endl; - //std::cout << d << " -> " << 32*(1+3*bitScanReverse32(1 * int(d) * int(d))) << std::endl; - */ + futilityValue = value_from_tt(tte->value(), ply) + FutilityValueMargin; // Loop through all legal moves until no moves remain or a beta cutoff occurs while ( bestValue < beta @@ -1511,28 +1507,23 @@ namespace { && !captureOrPromotion && move != ttMove) { - // History pruning. See ok_to_prune() definition - if ( moveCount >= MCLimit - && ok_to_prune(pos, move, ss[ply].threatMove, depth) + // Move count based pruning + if ( moveCount >= FutilityMoveCountMargin + && ok_to_prune(pos, move, ss[ply].threatMove) && bestValue > value_mated_in(PLY_MAX)) continue; // Value based pruning - if (approximateEval < beta) - {//dbg_before(); - if (futilityValue == VALUE_NONE) - futilityValue = evaluate(pos, ei, threadID) - + 56*(0+2*bitScanReverse32(1 * int(depth) * int(depth) / 2)); + if (futilityValue == VALUE_NONE) + futilityValue = evaluate(pos, ei, threadID) + FutilityValueMargin; - futilityValueScaled = futilityValue - moveCount * IncrementalFutilityMargin; + futilityValueScaled = futilityValue - moveCount * IncrementalFutilityMargin; - if (futilityValueScaled < beta) - { - if (futilityValueScaled > bestValue) - bestValue = futilityValueScaled; - continue; - } - //dbg_after(); // 36% (inc == 8), 40% (inc == 4), 37%(56) + if (futilityValueScaled < beta) + { + if (futilityValueScaled > bestValue) + bestValue = futilityValueScaled; + continue; } } @@ -1552,7 +1543,7 @@ namespace { value = -search(pos, ss, -(beta-1), newDepth-OnePly, ply+1, true, threadID); } else - value = beta; // Just to trigger next condition + value = beta; // Just to trigger next condition if (value >= beta) // Go with full depth non-pv search { @@ -1566,12 +1557,12 @@ namespace { // New best move? if (value > bestValue) { - bestValue = value; - if (value >= beta) - update_pv(ss, ply); + bestValue = value; + if (value >= beta) + update_pv(ss, ply); - if (value == value_mate_in(ply + 1)) - ss[ply].mateKiller = move; + if (value == value_mate_in(ply + 1)) + ss[ply].mateKiller = move; } // Split? @@ -1584,7 +1575,7 @@ namespace { && !thread_should_stop(threadID) && split(pos, ss, ply, &beta, &beta, &bestValue, futilityValue, approximateEval, depth, &moveCount, &mp, threadID, false)) - break; + break; } // All legal moves have been searched. A special case: If there were @@ -1663,10 +1654,10 @@ namespace { } ttMove = (tte ? tte->move() : MOVE_NONE); - // Evaluate the position statically isCheck = pos.is_check(); ei.futilityMargin = Value(0); // Manually initialize futilityMargin + // Evaluate the position statically if (isCheck) staticValue = -VALUE_INFINITE; @@ -1675,7 +1666,7 @@ namespace { // Use the cached evaluation score if possible assert(ei.futilityMargin == Value(0)); - staticValue = tte->value(); + staticValue = value_from_tt(tte->value(), ply); } else staticValue = evaluate(pos, ei, threadID); @@ -1820,6 +1811,9 @@ namespace { bool useFutilityPruning = sp->depth < SelectiveDepth && !isCheck; + const int FutilityMoveCountMargin = 3 + (1 << (3 * int(sp->depth) / 8)); + const int FutilityValueMargin = 112 * bitScanReverse32(int(sp->depth) * int(sp->depth) / 2); + while ( sp->bestValue < sp->beta && !thread_should_stop(threadID) && (move = sp->mp->get_next_move(sp->lock)) != MOVE_NONE) @@ -1845,33 +1839,31 @@ namespace { && !dangerous && !captureOrPromotion) { - // History pruning. See ok_to_prune() definition - if ( moveCount >= 2 + int(sp->depth) - && ok_to_prune(pos, move, ss[sp->ply].threatMove, sp->depth) + // Move count based pruning + if ( moveCount >= FutilityMoveCountMargin + && ok_to_prune(pos, move, ss[sp->ply].threatMove) && sp->bestValue > value_mated_in(PLY_MAX)) continue; // Value based pruning - if (sp->approximateEval < sp->beta) + if (sp->futilityValue == VALUE_NONE) { - if (sp->futilityValue == VALUE_NONE) - { - EvalInfo ei; - sp->futilityValue = evaluate(pos, ei, threadID) - + FutilityMargins[int(sp->depth) - 2]; - } + EvalInfo ei; + sp->futilityValue = evaluate(pos, ei, threadID) + FutilityValueMargin; + } + + Value futilityValueScaled = sp->futilityValue - moveCount * IncrementalFutilityMargin; - if (sp->futilityValue < sp->beta) + if (futilityValueScaled < sp->beta) + { + if (futilityValueScaled > sp->bestValue) // Less then 1% of cases { - 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; + lock_grab(&(sp->lock)); + if (futilityValueScaled > sp->bestValue) + sp->bestValue = futilityValueScaled; + lock_release(&(sp->lock)); } + continue; } } @@ -2469,14 +2461,13 @@ namespace { // non-tactical moves late in the move list close to the leaves are // candidates for pruning. - bool ok_to_prune(const Position& pos, Move m, Move threat, Depth d) { + bool ok_to_prune(const Position& pos, Move m, Move threat) { assert(move_is_ok(m)); assert(threat == MOVE_NONE || move_is_ok(threat)); assert(!pos.move_is_check(m)); assert(!pos.move_is_capture_or_promotion(m)); assert(!pos.move_is_passed_pawn_push(m)); - assert(d >= OnePly); Square mfrom, mto, tfrom, tto; @@ -2503,11 +2494,7 @@ namespace { && pos.move_attacks_square(m, tto)) return false; - // Case 4: Don't prune moves with good history - if (!H.ok_to_prune(pos.piece_on(mfrom), mto, d)) - return false; - - // Case 5: If the moving piece in the threatened move is a slider, don't + // Case 4: If the moving piece in the threatened move is a slider, don't // prune safe moves which block its ray. if ( !PruneBlockingMoves && threat != MOVE_NONE @@ -2528,8 +2515,8 @@ namespace { Value v = value_from_tt(tte->value(), ply); return ( tte->depth() >= depth - || v >= Max(value_mate_in(100), beta) - || v < Min(value_mated_in(100), beta)) + || v >= Max(value_mate_in(PLY_MAX), beta) + || v < Min(value_mated_in(PLY_MAX), beta)) && ( (is_lower_bound(tte->type()) && v >= beta) || (is_upper_bound(tte->type()) && v < beta)); @@ -2548,7 +2535,7 @@ namespace { { assert(m != movesSearched[i]); if (!pos.move_is_capture_or_promotion(movesSearched[i])) - H.failure(pos.piece_on(move_from(movesSearched[i])), move_to(movesSearched[i])); + H.failure(pos.piece_on(move_from(movesSearched[i])), move_to(movesSearched[i]), depth); } }