X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=4481cfc727e436b8888825c94ec4bc99d261b21e;hp=5bbc0abd2d58514870af54133786b3595dcdc563;hb=0d88b832e38430e0add9c8298458569b23e102a7;hpb=3f3365221b571f1e712f1dd66574a866e858256d diff --git a/src/search.cpp b/src/search.cpp index 5bbc0abd..4481cfc7 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 @@ -173,14 +173,14 @@ 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); // Razoring const Depth RazorDepth = 4*OnePly; @@ -288,7 +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); @@ -402,13 +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"); @@ -1435,7 +1435,7 @@ 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]; @@ -1510,9 +1510,9 @@ namespace { && !captureOrPromotion && move != ttMove) { - // History pruning. See ok_to_prune() definition + // Move count based pruning if ( moveCount >= FutilityMoveCountMargin - && ok_to_prune(pos, move, ss[ply].threatMove, depth) + && ok_to_prune(pos, move, ss[ply].threatMove) && bestValue > value_mated_in(PLY_MAX)) continue; @@ -1814,6 +1814,7 @@ 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 @@ -1841,32 +1842,31 @@ 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) + FutilityValueMargin; - } + EvalInfo ei; + sp->futilityValue = evaluate(pos, ei, threadID) + FutilityValueMargin; + } - if (sp->futilityValue < sp->beta) + Value futilityValueScaled = sp->futilityValue - moveCount * IncrementalFutilityMargin; + + 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; } } @@ -2464,14 +2464,13 @@ 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; @@ -2498,11 +2497,7 @@ 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 @@ -2523,8 +2518,8 @@ 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)); @@ -2543,7 +2538,7 @@ 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); } }