X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=9c5fb58bd8bbe283cadd3bf7f39ddb8671088ccd;hp=e6e53e7c59d147d16aaa588670dd989f7ad66f76;hb=64a63464d7bc72a3aac33aa680cd2b2b240ff903;hpb=e0bafa1911ede61b9268e0b461a5d8856d6cd6be diff --git a/src/search.cpp b/src/search.cpp index e6e53e7c..9c5fb58b 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -520,7 +520,7 @@ void Thread::search() { totBestMoveChanges += th->bestMoveChanges; th->bestMoveChanges = 0; } - double bestMoveInstability = 1 + totBestMoveChanges / Threads.size(); + double bestMoveInstability = 1 + 2 * totBestMoveChanges / Threads.size(); double totalTime = rootMoves.size() == 1 ? 0 : Time.optimum() * fallingEval * reduction * bestMoveInstability; @@ -597,7 +597,7 @@ namespace { Move ttMove, move, excludedMove, bestMove; Depth extension, newDepth; Value bestValue, value, ttValue, eval, maxValue, probCutBeta; - bool ttHit, formerPv, givesCheck, improving, didLMR, priorCapture; + bool formerPv, givesCheck, improving, didLMR, priorCapture; bool captureOrPromotion, doFullDepthSearch, moveCountPruning, ttCapture, singularQuietLMR; Piece movedPiece; @@ -654,9 +654,7 @@ namespace { // starts with statScore = 0. Later grandchildren start with the last calculated // statScore of the previous grandchild. This influences the reduction rules in // LMR which are based on the statScore of parent position. - if (rootNode) - (ss+4)->statScore = 0; - else + if (!rootNode) (ss+2)->statScore = 0; // Step 4. Transposition table lookup. We don't want the score of a partial @@ -664,12 +662,12 @@ namespace { // position key in case of an excluded move. excludedMove = ss->excludedMove; posKey = excludedMove == MOVE_NONE ? pos.key() : pos.key() ^ make_key(excludedMove); - tte = TT.probe(posKey, ttHit); - ttValue = ttHit ? value_from_tt(tte->value(), ss->ply, pos.rule50_count()) : VALUE_NONE; + tte = TT.probe(posKey, ss->ttHit); + ttValue = ss->ttHit ? value_from_tt(tte->value(), ss->ply, pos.rule50_count()) : VALUE_NONE; ttMove = rootNode ? thisThread->rootMoves[thisThread->pvIdx].pv[0] - : ttHit ? tte->move() : MOVE_NONE; + : ss->ttHit ? tte->move() : MOVE_NONE; if (!excludedMove) - ss->ttPv = PvNode || (ttHit && tte->is_pv()); + ss->ttPv = PvNode || (ss->ttHit && tte->is_pv()); formerPv = ss->ttPv && !PvNode; if ( ss->ttPv @@ -681,11 +679,11 @@ namespace { // thisThread->ttHitAverage can be used to approximate the running average of ttHit thisThread->ttHitAverage = (TtHitAverageWindow - 1) * thisThread->ttHitAverage / TtHitAverageWindow - + TtHitAverageResolution * ttHit; + + TtHitAverageResolution * ss->ttHit; // At non-PV nodes we check for an early TT cutoff if ( !PvNode - && ttHit + && ss->ttHit && tte->depth() >= depth && ttValue != VALUE_NONE // Possible in case of TT access race && (ttValue >= beta ? (tte->bound() & BOUND_LOWER) @@ -778,7 +776,7 @@ namespace { improving = false; goto moves_loop; } - else if (ttHit) + else if (ss->ttHit) { // Never assume anything about values stored in TT ss->staticEval = eval = tte->eval(); @@ -882,14 +880,14 @@ namespace { // there and in further interactions with transposition table cutoff depth is set to depth - 3 // because probCut search has depth set to depth - 4 but we also do a move before it // so effective depth is equal to depth - 3 - && !( ttHit + && !( ss->ttHit && tte->depth() >= depth - 3 && ttValue != VALUE_NONE && ttValue < probCutBeta)) { // if ttMove is a capture and value from transposition table is good enough produce probCut // cutoff without digging into actual probCut search - if ( ttHit + if ( ss->ttHit && tte->depth() >= depth - 3 && ttValue != VALUE_NONE && ttValue >= probCutBeta @@ -933,7 +931,7 @@ namespace { if (value >= probCutBeta) { // if transposition table doesn't have equal or more deep info write probCut data into it - if ( !(ttHit + if ( !(ss->ttHit && tte->depth() >= depth - 3 && ttValue != VALUE_NONE)) tte->save(posKey, value_to_tt(value, ss->ply), ttPv, @@ -1058,7 +1056,6 @@ moves_loop: // When in check, search starts from here if ( !givesCheck && lmrDepth < 6 && !(PvNode && abs(bestValue) < 2) - && PieceValue[MG][type_of(movedPiece)] >= PieceValue[MG][type_of(pos.piece_on(to_sq(move)))] && !ss->inCheck && ss->staticEval + 169 + 244 * lmrDepth + PieceValue[MG][type_of(pos.piece_on(to_sq(move)))] <= alpha) @@ -1129,11 +1126,6 @@ moves_loop: // When in check, search starts from here && pos.non_pawn_material() <= 2 * RookValueMg) extension = 1; - // Castling extension - if ( type_of(move) == CASTLING - && popcount(pos.pieces(us) & ~pos.pieces(PAWN) & (to_sq(move) & KingSide ? KingSide : QueenSide)) <= 2) - extension = 1; - // Late irreversible move extension if ( move == ttMove && pos.rule50_count() > 80 @@ -1160,7 +1152,6 @@ moves_loop: // When in check, search starts from here // re-searched at full depth. if ( depth >= 3 && moveCount > 1 + 2 * rootNode + 2 * (PvNode && abs(bestValue) < 2) - && (!rootNode || thisThread->best_move_count(move) == 0) && ( !captureOrPromotion || moveCountPruning || ss->staticEval + PieceValue[EG][pos.captured_piece()] <= alpha @@ -1169,13 +1160,6 @@ moves_loop: // When in check, search starts from here { Depth r = reduction(improving, depth, moveCount); - // Decrease reduction at non-check cut nodes for second move at low depths - if ( cutNode - && depth <= 10 - && moveCount <= 2 - && !ss->inCheck) - r--; - // Decrease reduction if the ttHit running average is large if (thisThread->ttHitAverage > 509 * TtHitAverageResolution * TtHitAverageWindow / 1024) r--; @@ -1197,7 +1181,7 @@ moves_loop: // When in check, search starts from here // Decrease reduction if ttMove has been singularly extended (~3 Elo) if (singularQuietLMR) - r -= 1 + formerPv; + r--; if (!captureOrPromotion) { @@ -1431,7 +1415,7 @@ moves_loop: // When in check, search starts from here Move ttMove, move, bestMove; Depth ttDepth; Value bestValue, value, ttValue, futilityValue, futilityBase, oldAlpha; - bool ttHit, pvHit, givesCheck, captureOrPromotion; + bool pvHit, givesCheck, captureOrPromotion; int moveCount; if (PvNode) @@ -1461,13 +1445,13 @@ moves_loop: // When in check, search starts from here : DEPTH_QS_NO_CHECKS; // Transposition table lookup posKey = pos.key(); - tte = TT.probe(posKey, ttHit); - ttValue = ttHit ? value_from_tt(tte->value(), ss->ply, pos.rule50_count()) : VALUE_NONE; - ttMove = ttHit ? tte->move() : MOVE_NONE; - pvHit = ttHit && tte->is_pv(); + tte = TT.probe(posKey, ss->ttHit); + ttValue = ss->ttHit ? value_from_tt(tte->value(), ss->ply, pos.rule50_count()) : VALUE_NONE; + ttMove = ss->ttHit ? tte->move() : MOVE_NONE; + pvHit = ss->ttHit && tte->is_pv(); if ( !PvNode - && ttHit + && ss->ttHit && tte->depth() >= ttDepth && ttValue != VALUE_NONE // Only in case of TT access race && (ttValue >= beta ? (tte->bound() & BOUND_LOWER) @@ -1482,7 +1466,7 @@ moves_loop: // When in check, search starts from here } else { - if (ttHit) + if (ss->ttHit) { // Never assume anything about values stored in TT if ((ss->staticEval = bestValue = tte->eval()) == VALUE_NONE) @@ -1501,7 +1485,7 @@ moves_loop: // When in check, search starts from here // Stand pat. Return immediately if static value is at least beta if (bestValue >= beta) { - if (!ttHit) + if (!ss->ttHit) tte->save(posKey, value_to_tt(bestValue, ss->ply), false, BOUND_LOWER, DEPTH_NONE, MOVE_NONE, ss->staticEval); @@ -1565,7 +1549,9 @@ moves_loop: // When in check, search starts from here } // Do not search moves with negative SEE values - if (!ss->inCheck && !pos.see_ge(move)) + if ( !ss->inCheck + && !(givesCheck && pos.is_discovery_check_on_king(~pos.side_to_move(), move)) + && !pos.see_ge(move)) continue; // Speculative prefetch as early as possible @@ -1717,8 +1703,8 @@ moves_loop: // When in check, search starts from here else captureHistory[moved_piece][to_sq(bestMove)][captured] << bonus1; - // Extra penalty for a quiet TT or main killer move in previous ply when it gets refuted - if ( ((ss-1)->moveCount == 1 || ((ss-1)->currentMove == (ss-1)->killers[0])) + // Extra penalty for a quiet early move that was not a TT move or main killer move in previous ply when it gets refuted + if ( ((ss-1)->moveCount == 1 + (ss-1)->ttHit || ((ss-1)->currentMove == (ss-1)->killers[0])) && !pos.captured_piece()) update_continuation_histories(ss-1, pos.piece_on(prevSq), prevSq, -bonus1); @@ -1861,12 +1847,15 @@ string UCI::pv(const Position& pos, Depth depth, Value alpha, Value beta) { { bool updated = rootMoves[i].score != -VALUE_INFINITE; - if (depth == 1 && !updated) + if (depth == 1 && !updated && i > 0) continue; - Depth d = updated ? depth : depth - 1; + Depth d = updated ? depth : std::max(1, depth - 1); Value v = updated ? rootMoves[i].score : rootMoves[i].previousScore; + if (v == -VALUE_INFINITE) + v = VALUE_ZERO; + bool tb = TB::RootInTB && abs(v) < VALUE_MATE_IN_MAX_PLY; v = tb ? rootMoves[i].tbScore : v; @@ -1964,7 +1953,7 @@ void Tablebases::rank_root_moves(Position& pos, Search::RootMoves& rootMoves) { if (RootInTB) { // Sort moves according to TB rank - std::sort(rootMoves.begin(), rootMoves.end(), + std::stable_sort(rootMoves.begin(), rootMoves.end(), [](const RootMove &a, const RootMove &b) { return a.tbRank > b.tbRank; } ); // Probe during search only if DTZ is not available and we are winning