X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=a26a9ab8cbc1092d8a34171cc7a5765a2aaf0c48;hp=08bf90f89845673b79b8197c40e17bab2eccc119;hb=883367d21749eb91a5a3737338b5a7f507751a5a;hpb=39257509452a81db28538462e6581b05d1a4b7fb diff --git a/src/search.cpp b/src/search.cpp index 08bf90f8..a26a9ab8 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -448,7 +448,7 @@ void Thread::search() { { beta = std::min(bestValue + delta, VALUE_INFINITE); if (mainThread) - ++failedHighCnt; + ++failedHighCnt; } else break; @@ -492,10 +492,8 @@ void Thread::search() { && !Threads.stop && !Threads.stopOnPonderhit) { - const int F[] = { failedLow, - bestValue - mainThread->previousScore }; - - int improvingFactor = std::max(246, std::min(832, 306 + 119 * F[0] - 6 * F[1])); + double fallingEval = (306 + 119 * failedLow + 6 * (mainThread->previousScore - bestValue)) / 581.0; + fallingEval = std::max(0.5, std::min(1.5, fallingEval)); // If the bestMove is stable over several iterations, reduce time accordingly timeReduction = 1.0; @@ -509,7 +507,7 @@ void Thread::search() { // Stop the search if we have only one legal move, or if available time elapsed if ( rootMoves.size() == 1 - || Time.elapsed() > Time.optimum() * bestMoveInstability * improvingFactor / 581) + || Time.elapsed() > Time.optimum() * bestMoveInstability * fallingEval) { // If we are allowed to ponder do not stop the search now but // keep pondering until the GUI sends "ponderhit" or "stop". @@ -683,6 +681,10 @@ 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); @@ -824,8 +826,8 @@ namespace { && depth >= 5 * ONE_PLY && abs(beta) < VALUE_MATE_IN_MAX_PLY) { - Value rbeta = std::min(beta + 216 - 48 * improving, VALUE_INFINITE); - MovePicker mp(pos, ttMove, rbeta - ss->staticEval, &thisThread->captureHistory); + Value raisedBeta = std::min(beta + 216 - 48 * improving, VALUE_INFINITE); + MovePicker mp(pos, ttMove, raisedBeta - ss->staticEval, &thisThread->captureHistory); int probCutCount = 0; while ( (move = mp.next_move()) != MOVE_NONE @@ -842,15 +844,15 @@ namespace { pos.do_move(move, st); // Perform a preliminary qsearch to verify that the move holds - value = -qsearch(pos, ss+1, -rbeta, -rbeta+1); + value = -qsearch(pos, ss+1, -raisedBeta, -raisedBeta+1); // If the qsearch held perform the regular search - if (value >= rbeta) - value = -search(pos, ss+1, -rbeta, -rbeta+1, depth - 4 * ONE_PLY, !cutNode); + if (value >= raisedBeta) + value = -search(pos, ss+1, -raisedBeta, -raisedBeta+1, depth - 4 * ONE_PLY, !cutNode); pos.undo_move(move); - if (value >= rbeta) + if (value >= raisedBeta) return value; } } @@ -926,26 +928,26 @@ moves_loop: // When in check, search starts from here if ( depth >= 8 * ONE_PLY && move == ttMove && !rootNode - && !excludedMove // Recursive singular search is not allowed + && !excludedMove // Avoid recursive singular search && ttValue != VALUE_NONE && (tte->bound() & BOUND_LOWER) && tte->depth() >= depth - 3 * ONE_PLY && pos.legal(move)) { - Value rBeta = std::max(ttValue - 2 * depth / ONE_PLY, -VALUE_MATE); + Value reducedBeta = std::max(ttValue - 2 * depth / ONE_PLY, -VALUE_MATE); ss->excludedMove = move; - value = search(pos, ss, rBeta - 1, rBeta, depth / 2, cutNode); + value = search(pos, ss, reducedBeta - 1, reducedBeta, depth / 2, cutNode); ss->excludedMove = MOVE_NONE; - if (value < rBeta) + if (value < reducedBeta) extension = ONE_PLY; } else if ( givesCheck // Check extension (~2 Elo) && 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 if castling + else if (type_of(move) == CASTLING) extension = ONE_PLY; // Calculate new depth for this move @@ -971,7 +973,7 @@ 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 + ((ss-1)->statScore > 0) + if ( lmrDepth < 3 + ((ss-1)->statScore > 0 || (ss-1)->moveCount == 1) && (*contHist[0])[movedPiece][to_sq(move)] < CounterMovePruneThreshold && (*contHist[1])[movedPiece][to_sq(move)] < CounterMovePruneThreshold) continue; @@ -1183,9 +1185,12 @@ moves_loop: // When in check, search starts from here 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()) - update_continuation_histories(ss-1, pos.piece_on(prevSq), prevSq, -stat_bonus(depth + ONE_PLY)); + // 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] && (ss-1)->killers[0])) + if (!pos.captured_piece()) + update_continuation_histories(ss-1, pos.piece_on(prevSq), prevSq, -stat_bonus(depth + ONE_PLY)); + } // Bonus for prior countermove that caused the fail low else if ( (depth >= 3 * ONE_PLY || PvNode) @@ -1391,21 +1396,15 @@ 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); - - return value; - } + else + break; // Fail high } } } @@ -1416,7 +1415,8 @@ 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, + bestValue >= beta ? BOUND_LOWER : + PvNode && bestValue > oldAlpha ? BOUND_EXACT : BOUND_UPPER, ttDepth, bestMove, ss->staticEval); assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);