X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=38d5683493a5b14df76a7196a340b49a8b429ebd;hp=0574da5897274c2653f82234675a08545de9c644;hb=6ab92d2e1c417fa7a9fd87eee0add2bf02112296;hpb=6b5d671cdc30751d79765edc8ae5320255ce120c diff --git a/src/search.cpp b/src/search.cpp index 0574da58..38d56834 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -2,7 +2,7 @@ Stockfish, a UCI chess playing engine derived from Glaurung 2.1 Copyright (C) 2004-2008 Tord Romstad (Glaurung author) Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad - Copyright (C) 2015-2018 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad + Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad Stockfish is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -66,21 +66,11 @@ namespace { constexpr int SkipPhase[] = { 0, 1, 0, 1, 2, 3, 0, 1, 2, 3, 4, 5, 0, 1, 2, 3, 4, 5, 6, 7 }; // Razor and futility margins - constexpr int RazorMargin[] = {0, 590, 604}; + constexpr int RazorMargin = 600; Value futility_margin(Depth d, bool improving) { return Value((175 - 50 * improving) * d / ONE_PLY); } - // Margin for pruning capturing moves: almost linear in depth - constexpr int CapturePruneMargin[] = { 0, - 1 * PawnValueEg * 1055 / 1000, - 2 * PawnValueEg * 1042 / 1000, - 3 * PawnValueEg * 963 / 1000, - 4 * PawnValueEg * 1038 / 1000, - 5 * PawnValueEg * 950 / 1000, - 6 * PawnValueEg * 930 / 1000 - }; - // Futility and reductions lookup tables, initialized at startup int FutilityMoveCounts[2][16]; // [improving][depth] int Reductions[2][2][64][64]; // [pv][improving][depth][moveNumber] @@ -92,7 +82,14 @@ namespace { // History and stats update bonus, based on depth int stat_bonus(Depth depth) { int d = depth / ONE_PLY; - return d > 17 ? 0 : 32 * d * d + 64 * d - 64; + return d > 17 ? 0 : 29 * d * d + 138 * d - 134; + } + + // Add a small random component to draw evaluations to keep search dynamic + // and to avoid 3fold-blindness. + Value value_draw(Depth depth, Thread* thisThread) { + return depth < 4 ? VALUE_DRAW + : VALUE_DRAW + Value(2 * (thisThread->nodes.load(std::memory_order_relaxed) % 2) - 1); } // Skill structure is used to implement strength limit @@ -190,6 +187,7 @@ void Search::clear() { Time.availableNodes = 0; TT.clear(); Threads.clear(); + Tablebases::init(Options["SyzygyPath"]); // Free up mapped files } @@ -256,15 +254,30 @@ void MainThread::search() { && !Skill(Options["Skill Level"]).enabled() && rootMoves[0].pv[0] != MOVE_NONE) { - for (Thread* th : Threads) + std::map votes; + Value minScore = this->rootMoves[0].score; + + // Find out minimum score and reset votes for moves which can be voted + for (Thread* th: Threads) { - Depth depthDiff = th->completedDepth - bestThread->completedDepth; - Value scoreDiff = th->rootMoves[0].score - bestThread->rootMoves[0].score; + minScore = std::min(minScore, th->rootMoves[0].score); + votes[th->rootMoves[0].pv[0]] = 0; + } + + // Vote according to score and depth + for (Thread* th : Threads) + votes[th->rootMoves[0].pv[0]] += int(th->rootMoves[0].score - minScore) + + int(th->completedDepth); - // Select the thread with the best score, always if it is a mate - if ( scoreDiff > 0 - && (depthDiff >= 0 || th->rootMoves[0].score >= VALUE_MATE_IN_MAX_PLY)) + // Select best thread + int bestVote = votes[this->rootMoves[0].pv[0]]; + for (Thread* th : Threads) + { + if (votes[th->rootMoves[0].pv[0]] > bestVote) + { + bestVote = votes[th->rootMoves[0].pv[0]]; bestThread = th; + } } } @@ -296,16 +309,17 @@ void Thread::search() { MainThread* mainThread = (this == Threads.main() ? Threads.main() : nullptr); double timeReduction = 1.0; Color us = rootPos.side_to_move(); + bool failedLow; std::memset(ss-4, 0, 7 * sizeof(Stack)); for (int i = 4; i > 0; i--) - (ss-i)->contHistory = this->contHistory[NO_PIECE][0].get(); // Use as sentinel + (ss-i)->continuationHistory = &this->continuationHistory[NO_PIECE][0]; // Use as sentinel bestValue = delta = alpha = -VALUE_INFINITE; beta = VALUE_INFINITE; if (mainThread) - mainThread->bestMoveChanges = 0, mainThread->failedLow = false; + mainThread->bestMoveChanges = 0, failedLow = false; size_t multiPV = Options["MultiPV"]; Skill skill(Options["Skill Level"]); @@ -340,13 +354,13 @@ void Thread::search() { if (idx > 0) { int i = (idx - 1) % 20; - if (((rootDepth / ONE_PLY + rootPos.game_ply() + SkipPhase[i]) / SkipSize[i]) % 2) + if (((rootDepth / ONE_PLY + SkipPhase[i]) / SkipSize[i]) % 2) continue; // Retry with an incremented rootDepth } // Age out PV variability metric if (mainThread) - mainThread->bestMoveChanges *= 0.517, mainThread->failedLow = false; + mainThread->bestMoveChanges *= 0.517, failedLow = false; // Save the last iteration's scores before first PV line is searched and // all the move scores except the (new) PV are set to -VALUE_INFINITE. @@ -374,7 +388,7 @@ void Thread::search() { if (rootDepth >= 5 * ONE_PLY) { Value previousScore = rootMoves[pvIdx].previousScore; - delta = Value(18); + delta = Value(20); alpha = std::max(previousScore - delta,-VALUE_INFINITE); beta = std::min(previousScore + delta, VALUE_INFINITE); @@ -388,9 +402,11 @@ void Thread::search() { // Start with a small aspiration window and, in the case of a fail // high/low, re-search with a bigger window until we don't fail // high/low anymore. + int failedHighCnt = 0; while (true) { - bestValue = ::search(rootPos, ss, alpha, beta, rootDepth, false); + Depth adjustedDepth = std::max(ONE_PLY, rootDepth - failedHighCnt * ONE_PLY); + bestValue = ::search(rootPos, ss, alpha, beta, adjustedDepth, false); // Bring the best move to the front. It is critical that sorting // is done with a stable algorithm because all the values but the @@ -423,12 +439,17 @@ void Thread::search() { if (mainThread) { - mainThread->failedLow = true; + failedHighCnt = 0; + failedLow = true; Threads.stopOnPonderhit = false; } } else if (bestValue >= beta) + { beta = std::min(bestValue + delta, VALUE_INFINITE); + if (mainThread) + ++failedHighCnt; + } else break; @@ -471,7 +492,7 @@ void Thread::search() { && !Threads.stop && !Threads.stopOnPonderhit) { - const int F[] = { mainThread->failedLow, + const int F[] = { failedLow, bestValue - mainThread->previousScore }; int improvingFactor = std::max(246, std::min(832, 306 + 119 * F[0] - 6 * F[1])); @@ -519,13 +540,25 @@ namespace { template Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth, bool cutNode) { - // Use quiescence search when needed - if (depth < ONE_PLY) - return qsearch(pos, ss, alpha, beta); - constexpr bool PvNode = NT == PV; const bool rootNode = PvNode && ss->ply == 0; + // Check if we have an upcoming move which draws by repetition, or + // if the opponent had an alternative move earlier to this position. + if ( pos.rule50_count() >= 3 + && alpha < VALUE_DRAW + && !rootNode + && pos.has_game_cycle(ss->ply)) + { + alpha = value_draw(depth, pos.this_thread()); + if (alpha >= beta) + return alpha; + } + + // Dive into quiescence search when the depth reaches zero + if (depth < ONE_PLY) + return qsearch(pos, ss, alpha, beta); + assert(-VALUE_INFINITE <= alpha && alpha < beta && beta <= VALUE_INFINITE); assert(PvNode || (alpha == beta - 1)); assert(DEPTH_ZERO < depth && depth < DEPTH_MAX); @@ -538,7 +571,7 @@ namespace { Key posKey; Move ttMove, move, excludedMove, bestMove; Depth extension, newDepth; - Value bestValue, value, ttValue, eval, maxValue; + Value bestValue, value, ttValue, eval, maxValue, pureStaticEval; bool ttHit, inCheck, givesCheck, improving; bool captureOrPromotion, doFullDepthSearch, moveCountPruning, skipQuiets, ttCapture, pvExact; Piece movedPiece; @@ -566,7 +599,8 @@ namespace { if ( Threads.stop.load(std::memory_order_relaxed) || pos.is_draw(ss->ply) || ss->ply >= MAX_PLY) - return (ss->ply >= MAX_PLY && !inCheck) ? evaluate(pos) : VALUE_DRAW; + return (ss->ply >= MAX_PLY && !inCheck) ? evaluate(pos) + : value_draw(depth, pos.this_thread()); // Step 3. Mate distance pruning. Even if we mate at the next move our score // would be at best mate_in(ss->ply+1), but if alpha is already bigger because @@ -578,24 +612,13 @@ namespace { beta = std::min(mate_in(ss->ply+1), beta); if (alpha >= beta) return alpha; - - // Check if there exists a move which draws by repetition, or an alternative - // earlier move to this position. - if ( pos.rule50_count() >= 3 - && alpha < VALUE_DRAW - && pos.has_game_cycle(ss->ply)) - { - alpha = VALUE_DRAW; - if (alpha >= beta) - return alpha; - } } assert(0 <= ss->ply && ss->ply < MAX_PLY); (ss+1)->ply = ss->ply + 1; ss->currentMove = (ss+1)->excludedMove = bestMove = MOVE_NONE; - ss->contHistory = thisThread->contHistory[NO_PIECE][0].get(); + ss->continuationHistory = &thisThread->continuationHistory[NO_PIECE][0]; (ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE; Square prevSq = to_sq((ss-1)->currentMove); @@ -660,6 +683,10 @@ namespace { TB::ProbeState err; TB::WDLScore wdl = Tablebases::probe_wdl(pos, &err); + // Force check of time on the next occasion + if (thisThread == Threads.main()) + static_cast(thisThread)->callsCnt = 0; + if (err != TB::ProbeState::FAIL) { thisThread->tbHits.fetch_add(1, std::memory_order_relaxed); @@ -678,7 +705,7 @@ namespace { { tte->save(posKey, value_to_tt(value, ss->ply), b, std::min(DEPTH_MAX - ONE_PLY, depth + 6 * ONE_PLY), - MOVE_NONE, VALUE_NONE, TT.generation()); + MOVE_NONE, VALUE_NONE); return value; } @@ -697,15 +724,16 @@ namespace { // Step 6. Static evaluation of the position if (inCheck) { - ss->staticEval = eval = VALUE_NONE; + ss->staticEval = eval = pureStaticEval = VALUE_NONE; improving = false; goto moves_loop; // Skip early pruning when in check } else if (ttHit) { // Never assume anything on values stored in TT - if ((ss->staticEval = eval = tte->eval()) == VALUE_NONE) - eval = ss->staticEval = evaluate(pos); + ss->staticEval = eval = pureStaticEval = tte->eval(); + if (eval == VALUE_NONE) + ss->staticEval = eval = pureStaticEval = evaluate(pos); // Can ttValue be used as a better position evaluation? if ( ttValue != VALUE_NONE @@ -714,24 +742,25 @@ namespace { } else { - ss->staticEval = eval = - (ss-1)->currentMove != MOVE_NULL ? evaluate(pos) - : -(ss-1)->staticEval + 2 * Eval::Tempo; + if ((ss-1)->currentMove != MOVE_NULL) + { + int p = (ss-1)->statScore; + int bonus = p > 0 ? (-p - 2500) / 512 : + p < 0 ? (-p + 2500) / 512 : 0; - tte->save(posKey, VALUE_NONE, BOUND_NONE, DEPTH_NONE, MOVE_NONE, - ss->staticEval, TT.generation()); + pureStaticEval = evaluate(pos); + ss->staticEval = eval = pureStaticEval + bonus; + } + else + ss->staticEval = eval = pureStaticEval = -(ss-1)->staticEval + 2 * Eval::Tempo; + + tte->save(posKey, VALUE_NONE, BOUND_NONE, DEPTH_NONE, MOVE_NONE, pureStaticEval); } // Step 7. Razoring (~2 Elo) - if ( !PvNode - && depth < 3 * ONE_PLY - && eval <= alpha - RazorMargin[depth / ONE_PLY]) - { - Value ralpha = alpha - (depth >= 2 * ONE_PLY) * RazorMargin[depth / ONE_PLY]; - Value v = qsearch(pos, ss, ralpha, ralpha+1); - if (depth < 2 * ONE_PLY || v <= ralpha) - return v; - } + if ( depth < 2 * ONE_PLY + && eval <= alpha - RazorMargin) + return qsearch(pos, ss, alpha, beta); improving = ss->staticEval >= (ss-2)->staticEval || (ss-2)->staticEval == VALUE_NONE; @@ -746,20 +775,20 @@ namespace { // Step 9. Null move search with verification search (~40 Elo) if ( !PvNode && (ss-1)->currentMove != MOVE_NULL - && (ss-1)->statScore < 22500 + && (ss-1)->statScore < 23200 && eval >= beta - && ss->staticEval >= beta - 36 * depth / ONE_PLY + 225 + && pureStaticEval >= beta - 36 * depth / ONE_PLY + 225 && !excludedMove && pos.non_pawn_material(us) - && (ss->ply > thisThread->nmpMinPly || us != thisThread->nmpColor)) + && (ss->ply >= thisThread->nmpMinPly || us != thisThread->nmpColor)) { assert(eval - beta >= 0); // Null move dynamic reduction based on depth and value - Depth R = ((823 + 67 * depth / ONE_PLY) / 256 + std::min((eval - beta) / PawnValueMg, 3)) * ONE_PLY; + Depth R = ((823 + 67 * depth / ONE_PLY) / 256 + std::min(int(eval - beta) / 200, 3)) * ONE_PLY; ss->currentMove = MOVE_NULL; - ss->contHistory = thisThread->contHistory[NO_PIECE][0].get(); + ss->continuationHistory = &thisThread->continuationHistory[NO_PIECE][0]; pos.do_null_move(st); @@ -780,7 +809,7 @@ namespace { // Do verification search at high depths, with null move pruning disabled // for us, until ply exceeds nmpMinPly. - thisThread->nmpMinPly = ss->ply + 3 * (depth-R) / 4 - 1; + thisThread->nmpMinPly = ss->ply + 3 * (depth-R) / 4; thisThread->nmpColor = us; Value v = search(pos, ss, beta-1, beta, depth-R, false); @@ -805,12 +834,12 @@ namespace { while ( (move = mp.next_move()) != MOVE_NONE && probCutCount < 3) - if (pos.legal(move)) + if (move != excludedMove && pos.legal(move)) { probCutCount++; ss->currentMove = move; - ss->contHistory = thisThread->contHistory[pos.moved_piece(move)][to_sq(move)].get(); + ss->continuationHistory = &thisThread->continuationHistory[pos.moved_piece(move)][to_sq(move)]; assert(depth >= 5 * ONE_PLY); @@ -843,7 +872,7 @@ namespace { moves_loop: // When in check, search starts from here - const PieceToHistory* contHist[] = { (ss-1)->contHistory, (ss-2)->contHistory, nullptr, (ss-4)->contHistory }; + const PieceToHistory* contHist[] = { (ss-1)->continuationHistory, (ss-2)->continuationHistory, nullptr, (ss-4)->continuationHistory }; Move countermove = thisThread->counterMoves[pos.piece_on(prevSq)][prevSq]; MovePicker mp(pos, ttMove, depth, &thisThread->mainHistory, @@ -854,7 +883,7 @@ moves_loop: // When in check, search starts from here value = bestValue; // Workaround a bogus 'uninitialized' warning under gcc skipQuiets = false; - ttCapture = false; + ttCapture = ttMove && pos.capture_or_promotion(ttMove); pvExact = PvNode && ttHit && tte->bound() == BOUND_EXACT; // Step 12. Loop through all pseudo-legal moves until no moves remain @@ -896,7 +925,7 @@ moves_loop: // When in check, search starts from here // Singular extension search (~60 Elo). If all moves but one fail low on a // search of (alpha-s, beta-s), and just one fails high on (alpha, beta), // then that move is singular and should be extended. To verify this we do - // a reduced search on on all the other moves but the ttMove and if the + // a reduced search on all the other moves but the ttMove and if the // result is lower than ttValue minus a margin then we will extend the ttMove. if ( depth >= 8 * ONE_PLY && move == ttMove @@ -916,10 +945,13 @@ moves_loop: // When in check, search starts from here extension = ONE_PLY; } else if ( givesCheck // Check extension (~2 Elo) - && !moveCountPruning && pos.see_ge(move)) extension = ONE_PLY; + else if ( pos.can_castle(us) // Extension for king moves that change castling rights + && type_of(movedPiece) == KING) + extension = ONE_PLY; + // Calculate new depth for this move newDepth = depth - ONE_PLY + extension; @@ -943,7 +975,7 @@ moves_loop: // When in check, search starts from here int lmrDepth = std::max(newDepth - reduction(improving, depth, moveCount), DEPTH_ZERO) / ONE_PLY; // Countermoves based pruning (~20 Elo) - if ( lmrDepth < 3 + if ( lmrDepth < 3 + ((ss-1)->statScore > 0) && (*contHist[0])[movedPiece][to_sq(move)] < CounterMovePruneThreshold && (*contHist[1])[movedPiece][to_sq(move)] < CounterMovePruneThreshold) continue; @@ -955,13 +987,11 @@ moves_loop: // When in check, search starts from here continue; // Prune moves with negative SEE (~10 Elo) - if ( lmrDepth < 8 - && !pos.see_ge(move, Value(-35 * lmrDepth * lmrDepth))) + if (!pos.see_ge(move, Value(-29 * lmrDepth * lmrDepth))) continue; } - else if ( depth < 7 * ONE_PLY // (~20 Elo) - && !extension - && !pos.see_ge(move, -Value(CapturePruneMargin[depth / ONE_PLY]))) + else if ( !extension // (~20 Elo) + && !pos.see_ge(move, -PawnValueEg * (depth / ONE_PLY))) continue; } @@ -975,12 +1005,9 @@ moves_loop: // When in check, search starts from here continue; } - if (move == ttMove && captureOrPromotion) - ttCapture = true; - // Update the current move (this must be done after singular extension search) ss->currentMove = move; - ss->contHistory = thisThread->contHistory[movedPiece][to_sq(move)].get(); + ss->continuationHistory = &thisThread->continuationHistory[movedPiece][to_sq(move)]; // Step 15. Make the move pos.do_move(move, st, givesCheck); @@ -993,20 +1020,12 @@ moves_loop: // When in check, search starts from here { Depth r = reduction(improving, depth, moveCount); - if (captureOrPromotion) // (~5 Elo) - { - // Increase reduction by comparing opponent's stat score - if ((ss-1)->statScore >= 0) - r += ONE_PLY; + // Decrease reduction if opponent's move count is high (~10 Elo) + if ((ss-1)->moveCount > 15) + r -= ONE_PLY; - r -= r ? ONE_PLY : DEPTH_ZERO; - } - else + if (!captureOrPromotion) { - // Decrease reduction if opponent's move count is high (~5 Elo) - if ((ss-1)->moveCount > 15) - r -= ONE_PLY; - // Decrease reduction for exact PV nodes (~0 Elo) if (pvExact) r -= ONE_PLY; @@ -1040,10 +1059,10 @@ moves_loop: // When in check, search starts from here r += ONE_PLY; // Decrease/increase reduction for moves with a good/bad history (~30 Elo) - r = std::max(DEPTH_ZERO, (r / ONE_PLY - ss->statScore / 20000) * ONE_PLY); + r -= ss->statScore / 20000 * ONE_PLY; } - Depth d = std::max(newDepth - r, ONE_PLY); + Depth d = std::max(newDepth - std::max(r, DEPTH_ZERO), ONE_PLY); value = -search(pos, ss+1, -(alpha+1), -alpha, d, true); @@ -1163,10 +1182,10 @@ moves_loop: // When in check, search starts from here { // Quiet best move: update move sorting heuristics if (!pos.capture_or_promotion(bestMove)) - update_quiet_stats(pos, ss, bestMove, quietsSearched, quietCount, stat_bonus(depth)); - else - update_capture_stats(pos, bestMove, capturesSearched, captureCount, - stat_bonus(depth + (bestValue > beta + KnightValueMg ? ONE_PLY : DEPTH_ZERO))); + update_quiet_stats(pos, ss, bestMove, quietsSearched, quietCount, + stat_bonus(depth + (bestValue > beta + PawnValueMg ? ONE_PLY : DEPTH_ZERO))); + + update_capture_stats(pos, bestMove, capturesSearched, captureCount, stat_bonus(depth + ONE_PLY)); // Extra penalty for a quiet TT move in previous ply when it gets refuted if ((ss-1)->moveCount == 1 && !pos.captured_piece()) @@ -1185,7 +1204,7 @@ moves_loop: // When in check, search starts from here tte->save(posKey, value_to_tt(bestValue, ss->ply), bestValue >= beta ? BOUND_LOWER : PvNode && bestMove ? BOUND_EXACT : BOUND_UPPER, - depth, bestMove, ss->staticEval, TT.generation()); + depth, bestMove, pureStaticEval); assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE); @@ -1222,8 +1241,10 @@ moves_loop: // When in check, search starts from here ss->pv[0] = MOVE_NONE; } + Thread* thisThread = pos.this_thread(); (ss+1)->ply = ss->ply + 1; ss->currentMove = bestMove = MOVE_NONE; + ss->continuationHistory = &thisThread->continuationHistory[NO_PIECE][0]; inCheck = pos.checkers(); moveCount = 0; @@ -1249,8 +1270,8 @@ moves_loop: // When in check, search starts from here && ttHit && tte->depth() >= ttDepth && ttValue != VALUE_NONE // Only in case of TT access race - && (ttValue >= beta ? (tte->bound() & BOUND_LOWER) - : (tte->bound() & BOUND_UPPER))) + && (ttValue >= beta ? (tte->bound() & BOUND_LOWER) + : (tte->bound() & BOUND_UPPER))) return ttValue; // Evaluate the position statically @@ -1268,7 +1289,7 @@ moves_loop: // When in check, search starts from here ss->staticEval = bestValue = evaluate(pos); // Can ttValue be used as a better position evaluation? - if ( ttValue != VALUE_NONE + if ( ttValue != VALUE_NONE && (tte->bound() & (ttValue > bestValue ? BOUND_LOWER : BOUND_UPPER))) bestValue = ttValue; } @@ -1282,7 +1303,7 @@ moves_loop: // When in check, search starts from here { if (!ttHit) tte->save(posKey, value_to_tt(bestValue, ss->ply), BOUND_LOWER, - DEPTH_NONE, MOVE_NONE, ss->staticEval, TT.generation()); + DEPTH_NONE, MOVE_NONE, ss->staticEval); return bestValue; } @@ -1293,12 +1314,15 @@ moves_loop: // When in check, search starts from here futilityBase = bestValue + 128; } + const PieceToHistory* contHist[] = { (ss-1)->continuationHistory, (ss-2)->continuationHistory, nullptr, (ss-4)->continuationHistory }; + // Initialize a MovePicker object for the current position, and prepare // to search the moves. Because the depth is <= 0 here, only captures, // queen promotions and checks (only if depth >= DEPTH_QS_CHECKS) will // be generated. - MovePicker mp(pos, ttMove, depth, &pos.this_thread()->mainHistory, - &pos.this_thread()->captureHistory, + MovePicker mp(pos, ttMove, depth, &thisThread->mainHistory, + &thisThread->captureHistory, + contHist, to_sq((ss-1)->currentMove)); // Loop through the moves until no moves remain or a beta cutoff occurs @@ -1355,6 +1379,7 @@ moves_loop: // When in check, search starts from here } ss->currentMove = move; + ss->continuationHistory = &thisThread->continuationHistory[pos.moved_piece(move)][to_sq(move)]; // Make and search the move pos.do_move(move, st, givesCheck); @@ -1370,21 +1395,15 @@ moves_loop: // When in check, search starts from here if (value > alpha) { + bestMove = move; + if (PvNode) // Update pv even in fail-high case update_pv(ss->pv, move, (ss+1)->pv); if (PvNode && value < beta) // Update alpha here! - { alpha = value; - bestMove = move; - } - else // Fail high - { - tte->save(posKey, value_to_tt(value, ss->ply), BOUND_LOWER, - ttDepth, move, ss->staticEval, TT.generation()); - - return value; - } + else + break; // Fail high } } } @@ -1395,8 +1414,9 @@ moves_loop: // When in check, search starts from here return mated_in(ss->ply); // Plies to mate from the root tte->save(posKey, value_to_tt(bestValue, ss->ply), - PvNode && bestValue > oldAlpha ? BOUND_EXACT : BOUND_UPPER, - ttDepth, bestMove, ss->staticEval, TT.generation()); + bestValue >= beta ? BOUND_LOWER : + PvNode && bestValue > oldAlpha ? BOUND_EXACT : BOUND_UPPER, + ttDepth, bestMove, ss->staticEval); assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE); @@ -1446,7 +1466,7 @@ moves_loop: // When in check, search starts from here for (int i : {1, 2, 4}) if (is_ok((ss-i)->currentMove)) - (*(ss-i)->contHistory)[pc][to] << bonus; + (*(ss-i)->continuationHistory)[pc][to] << bonus; } @@ -1458,7 +1478,9 @@ moves_loop: // When in check, search starts from here CapturePieceToHistory& captureHistory = pos.this_thread()->captureHistory; Piece moved_piece = pos.moved_piece(move); PieceType captured = type_of(pos.piece_on(to_sq(move))); - captureHistory[moved_piece][to_sq(move)][captured] << bonus; + + if (pos.capture_or_promotion(move)) + captureHistory[moved_piece][to_sq(move)][captured] << bonus; // Decrease all the other played capture moves for (int i = 0; i < captureCnt; ++i)