X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=78a1f7b6eb9e038a5c24f415dd127a2ddb67c13b;hp=e5f286e459721321d63e67e437e3b96d8a5e9120;hb=027626db1e449597ba2211a0819f251beda37b88;hpb=a5e68d9b25539b86304a9fb26afc616dc8126a1c diff --git a/src/search.cpp b/src/search.cpp index e5f286e4..78a1f7b6 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -164,6 +164,8 @@ namespace { uint64_t perft(Position& pos, Depth depth) { StateInfo st; + ASSERT_ALIGNED(&st, Eval::NNUE::kCacheLineSize); + uint64_t cnt, nodes = 0; const bool leaf = (depth == 2); @@ -192,7 +194,7 @@ namespace { void Search::init() { for (int i = 1; i < MAX_MOVES; ++i) - Reductions[i] = int((22.0 + 2 * std::log(Threads.size())) * std::log(i)); + Reductions[i] = int((22.0 + 2 * std::log(Threads.size())) * std::log(i + 0.25 * std::log(i))); } @@ -417,7 +419,7 @@ 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; + failedHighCnt = 0; while (true) { Depth adjustedDepth = std::max(1, rootDepth - failedHighCnt - searchAgainCounter); @@ -519,10 +521,14 @@ void Thread::search() { } double bestMoveInstability = 1 + 2 * totBestMoveChanges / Threads.size(); - double totalTime = rootMoves.size() == 1 ? 0 : - Time.optimum() * fallingEval * reduction * bestMoveInstability; + double totalTime = Time.optimum() * fallingEval * reduction * bestMoveInstability; + + // Cap used time in case of a single legal move for a better viewer experience in tournaments + // yielding correct scores and sufficiently fast moves. + if (rootMoves.size() == 1) + totalTime = std::min(500.0, totalTime); - // Stop the search if we have exceeded the totalTime, at least 1ms search + // Stop the search if we have exceeded the totalTime if (Time.elapsed() > totalTime) { // If we are allowed to ponder do not stop the search now but @@ -565,6 +571,7 @@ namespace { constexpr bool PvNode = NT == PV; const bool rootNode = PvNode && ss->ply == 0; + const Depth maxNextDepth = rootNode ? depth : depth + 1; // Check if we have an upcoming move which draws by repetition, or // if the opponent had an alternative move earlier to this position. @@ -589,6 +596,8 @@ namespace { Move pv[MAX_PLY+1], capturesSearched[32], quietsSearched[64]; StateInfo st; + ASSERT_ALIGNED(&st, Eval::NNUE::kCacheLineSize); + TTEntry* tte; Key posKey; Move ttMove, move, excludedMove, bestMove; @@ -1049,16 +1058,7 @@ moves_loop: // When in check, search starts from here && captureHistory[movedPiece][to_sq(move)][type_of(pos.piece_on(to_sq(move)))] < 0) continue; - // Futility pruning for captures - if ( !givesCheck - && lmrDepth < 6 - && !(PvNode && abs(bestValue) < 2) - && !ss->inCheck - && ss->staticEval + 169 + 244 * lmrDepth - + PieceValue[MG][type_of(pos.piece_on(to_sq(move)))] <= alpha) - continue; - - // See based pruning + // SEE based pruning if (!pos.see_ge(move, Value(-221) * depth)) // (~25 Elo) continue; } @@ -1161,7 +1161,7 @@ moves_loop: // When in check, search starts from here if (thisThread->ttHitAverage > 509 * TtHitAverageResolution * TtHitAverageWindow / 1024) r--; - // Reduction if other threads are searching this position + // Increase reduction if other threads are searching this position if (th.marked()) r++; @@ -1169,6 +1169,10 @@ moves_loop: // When in check, search starts from here if (ss->ttPv) r -= 2; + // Increase reduction at root and non-PV nodes when the best move does not change frequently + if ((rootNode || !PvNode) && depth > 10 && thisThread->bestMoveChanges <= 2) + r++; + if (moveCountPruning && !formerPv) r++; @@ -1186,6 +1190,9 @@ moves_loop: // When in check, search starts from here if (ttCapture) r++; + // Increase reduction at root if failing high + r += rootNode ? thisThread->failedHighCnt * thisThread->failedHighCnt * moveCount / 512 : 0; + // Increase reduction for cut nodes (~10 Elo) if (cutNode) r += 2; @@ -1265,7 +1272,8 @@ moves_loop: // When in check, search starts from here (ss+1)->pv = pv; (ss+1)->pv[0] = MOVE_NONE; - value = -search(pos, ss+1, -beta, -alpha, newDepth, false); + value = -search(pos, ss+1, -beta, -alpha, + std::min(maxNextDepth, newDepth), false); } // Step 18. Undo move @@ -1407,6 +1415,8 @@ moves_loop: // When in check, search starts from here Move pv[MAX_PLY+1]; StateInfo st; + ASSERT_ALIGNED(&st, Eval::NNUE::kCacheLineSize); + TTEntry* tte; Key posKey; Move ttMove, move, bestMove; @@ -1519,7 +1529,7 @@ moves_loop: // When in check, search starts from here moveCount++; // Futility pruning - if ( !ss->inCheck + if ( bestValue > VALUE_TB_LOSS_IN_MAX_PLY && !givesCheck && futilityBase > -VALUE_KNOWN_WIN && !pos.advanced_pawn_push(move)) @@ -1546,7 +1556,7 @@ moves_loop: // When in check, search starts from here } // Do not search moves with negative SEE values - if ( !ss->inCheck + if ( bestValue > VALUE_TB_LOSS_IN_MAX_PLY && !(givesCheck && pos.is_discovery_check_on_king(~pos.side_to_move(), move)) && !pos.see_ge(move)) continue; @@ -1569,7 +1579,7 @@ moves_loop: // When in check, search starts from here // CounterMove based pruning if ( !captureOrPromotion - && moveCount + && bestValue > VALUE_TB_LOSS_IN_MAX_PLY && (*contHist[0])[pos.moved_piece(move)][to_sq(move)] < CounterMovePruneThreshold && (*contHist[1])[pos.moved_piece(move)][to_sq(move)] < CounterMovePruneThreshold) continue; @@ -1604,7 +1614,11 @@ moves_loop: // When in check, search starts from here // All legal moves have been searched. A special case: if we're in check // and no legal moves were found, it is checkmate. if (ss->inCheck && bestValue == -VALUE_INFINITE) + { + assert(!MoveList(pos).size()); + return mated_in(ss->ply); // Plies to mate from the root + } tte->save(posKey, value_to_tt(bestValue, ss->ply), pvHit, bestValue >= beta ? BOUND_LOWER : @@ -1898,6 +1912,8 @@ string UCI::pv(const Position& pos, Depth depth, Value alpha, Value beta) { bool RootMove::extract_ponder_from_tt(Position& pos) { StateInfo st; + ASSERT_ALIGNED(&st, Eval::NNUE::kCacheLineSize); + bool ttHit; assert(pv.size() == 1);