X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=5ae2cf69f54dad439df37f5130245289b1fd0562;hp=7e9b8d77216ae788475f4e7b351297d8b21dcdf8;hb=691ed425bae1e0a24a12dc3c38534c07adf5221e;hpb=72f7282ad4da0584c87163aed85bd5ff4d633cd3 diff --git a/src/search.cpp b/src/search.cpp index 7e9b8d77..5ae2cf69 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -19,6 +19,7 @@ #include #include +#include #include #include #include @@ -55,9 +56,6 @@ namespace { // Set to true to force running with one thread. Used for debugging const bool FakeSplit = false; - // This is the minimum interval in msec between two check_time() calls - const int TimerResolution = 5; - // Different node types, used as template parameter enum NodeType { Root, PV, NonPV, SplitPointRoot, SplitPointPV, SplitPointNonPV }; @@ -65,13 +63,10 @@ namespace { inline Value razor_margin(Depth d) { return Value(512 + 16 * int(d)); } // Futility lookup tables (initialized at startup) and their access functions - Value FutilityMargins[16][64]; // [depth][moveNumber] int FutilityMoveCounts[2][32]; // [improving][depth] - inline Value futility_margin(Depth d, int mn) { - - return d < 7 * ONE_PLY ? FutilityMargins[std::max(int(d), 1)][std::min(mn, 63)] - : 2 * VALUE_INFINITE; + inline Value futility_margin(Depth d) { + return Value(100 * int(d)); } // Reduction lookup tables (initialized at startup) and their access function @@ -148,10 +143,6 @@ void Search::init() { Reductions[0][0][hd][mc] += ONE_PLY / 2; } - // Init futility margins array - for (d = 1; d < 16; ++d) for (mc = 0; mc < 64; ++mc) - FutilityMargins[d][mc] = Value(112 * int(2.9 * log(double(d))) - 8 * mc + 45); - // Init futility move count array for (d = 0; d < 32; ++d) { @@ -243,19 +234,12 @@ void Search::think() { Threads[i]->maxPly = 0; Threads.sleepWhileIdle = Options["Idle Threads Sleep"]; - - // Set best timer interval to avoid lagging under time pressure. Timer is - // used to check for remaining available thinking time. - Threads.timer->msec = - Limits.use_time_management() ? std::min(100, std::max(TimeMgr.available_time() / 16, TimerResolution)) : - Limits.nodes ? 2 * TimerResolution - : 100; - + Threads.timer->run = true; Threads.timer->notify_one(); // Wake up the recurring timer id_loop(RootPos); // Let's start searching ! - Threads.timer->msec = 0; // Stop the timer + Threads.timer->run = false; // Stop the timer Threads.sleepWhileIdle = true; // Send idle threads to sleep if (Options["Write Search Log"]) @@ -344,7 +328,7 @@ namespace { RootMoves[i].prevScore = RootMoves[i].score; // MultiPV loop. We perform a full root search for each PV line - for (PVIdx = 0; PVIdx < PVSize; ++PVIdx) + for (PVIdx = 0; PVIdx < PVSize && !Signals.stop; ++PVIdx) { // Reset aspiration window starting size if (depth >= 5) @@ -373,11 +357,11 @@ namespace { for (size_t i = 0; i <= PVIdx; ++i) RootMoves[i].insert_pv_in_tt(pos); - // If search has been stopped return immediately. Sorting and + // If search has been stopped break immediately. Sorting and // writing PV back to TT is safe becuase RootMoves is still // valid, although refers to previous iteration. if (Signals.stop) - return; + break; // When failing high/low give some update (without cluttering // the UI) before to research. @@ -434,7 +418,7 @@ namespace { Signals.stop = true; // Do we have time for the next iteration? Can we stop searching now? - if (Limits.use_time_management() && !Signals.stopOnPonderhit) + if (Limits.use_time_management() && !Signals.stop && !Signals.stopOnPonderhit) { bool stop = false; // Local variable, not the volatile Signals.stop @@ -450,6 +434,7 @@ namespace { // Stop search early if one move seems to be much better than others if ( depth >= 12 + && BestMoveChanges <= DBL_EPSILON && !stop && PVSize == 1 && bestValue > VALUE_MATED_IN_MAX_PLY @@ -505,9 +490,8 @@ namespace { SplitPoint* splitPoint; Key posKey; Move ttMove, move, excludedMove, bestMove, threatMove; - Depth ext, newDepth; - Value bestValue, value, ttValue; - Value eval, nullValue, futilityValue; + Depth ext, newDepth, predictedDepth; + Value bestValue, value, ttValue, eval, nullValue, futilityValue; bool inCheck, givesCheck, pvMove, singularExtensionNode, improving; bool captureOrPromotion, dangerous, doFullDepthSearch; int moveCount, quietCount; @@ -515,6 +499,7 @@ namespace { // Step 1. Initialize node Thread* thisThread = pos.this_thread(); inCheck = pos.checkers(); + excludedMove = ss->excludedMove; if (SpNode) { @@ -523,7 +508,7 @@ namespace { threatMove = splitPoint->threatMove; bestValue = splitPoint->bestValue; tte = NULL; - ttMove = excludedMove = MOVE_NONE; + ttMove = MOVE_NONE; ttValue = VALUE_NONE; assert(splitPoint->bestValue > -VALUE_INFINITE && splitPoint->moveCount > 0); @@ -535,7 +520,6 @@ namespace { bestValue = -VALUE_INFINITE; ss->currentMove = threatMove = (ss+1)->excludedMove = bestMove = MOVE_NONE; ss->ply = (ss-1)->ply + 1; - ss->futilityMoveCount = 0; (ss+1)->skipNullMove = false; (ss+1)->reduction = DEPTH_ZERO; (ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE; @@ -564,7 +548,6 @@ namespace { // Step 4. Transposition table lookup // We don't want the score of a partial search to overwrite a previous full search // TT value, so we use a different position key in case of an excluded move. - excludedMove = ss->excludedMove; posKey = excludedMove ? pos.exclusion_key() : pos.key(); tte = TT.probe(posKey); ttMove = RootNode ? RootMoves[PVIdx].pv[0] : tte ? tte->move() : MOVE_NONE; @@ -599,16 +582,15 @@ namespace { // Step 5. Evaluate the position statically and update parent's gain statistics if (inCheck) { - ss->staticEval = ss->evalMargin = eval = VALUE_NONE; + ss->staticEval = eval = VALUE_NONE; goto moves_loop; } else if (tte) { // Never assume anything on values stored in TT - if ( (ss->staticEval = eval = tte->eval_value()) == VALUE_NONE - ||(ss->evalMargin = tte->eval_margin()) == VALUE_NONE) - eval = ss->staticEval = evaluate(pos, ss->evalMargin); + if ((ss->staticEval = eval = tte->eval_value()) == VALUE_NONE) + eval = ss->staticEval = evaluate(pos); // Can ttValue be used as a better position evaluation? if (ttValue != VALUE_NONE) @@ -617,13 +599,10 @@ namespace { } else { - eval = ss->staticEval = evaluate(pos, ss->evalMargin); - TT.store(posKey, VALUE_NONE, BOUND_NONE, DEPTH_NONE, MOVE_NONE, - ss->staticEval, ss->evalMargin); + eval = ss->staticEval = evaluate(pos); + TT.store(posKey, VALUE_NONE, BOUND_NONE, DEPTH_NONE, MOVE_NONE, ss->staticEval); } - // Update gain for the parent non-capture move given the static position - // evaluation before and after the move. if ( !pos.captured_piece_type() && ss->staticEval != VALUE_NONE && (ss-1)->staticEval != VALUE_NONE @@ -650,17 +629,15 @@ namespace { return v; } - // Step 7. Static null move pruning (skipped when in check) - // We're betting that the opponent doesn't have a move that will reduce - // the score by more than futility_margin(depth) if we do a null move. + // Step 7. Futility pruning: child node (skipped when in check) if ( !PvNode && !ss->skipNullMove - && depth < 4 * ONE_PLY - && eval - futility_margin(depth, (ss-1)->futilityMoveCount) >= beta + && depth < 7 * ONE_PLY + && eval - futility_margin(depth) >= beta && abs(beta) < VALUE_MATE_IN_MAX_PLY && abs(eval) < VALUE_KNOWN_WIN && pos.non_pawn_material(pos.side_to_move())) - return eval - futility_margin(depth, (ss-1)->futilityMoveCount); + return eval - futility_margin(depth); // Step 8. Null move search with verification search (is omitted in PV nodes) if ( !PvNode @@ -863,7 +840,7 @@ moves_loop: // When in check and at SpNode search starts from here // Update current move (this must be done after singular extension search) newDepth = depth - ONE_PLY + ext; - // Step 13. Futility pruning (is omitted in PV nodes) + // Step 13. Pruning at shallow depth (exclude PV nodes) if ( !PvNode && !captureOrPromotion && !inCheck @@ -882,29 +859,30 @@ moves_loop: // When in check and at SpNode search starts from here continue; } - // Value based pruning - // We illogically ignore reduction condition depth >= 3*ONE_PLY for predicted depth, - // but fixing this made program slightly weaker. - Depth predictedDepth = newDepth - reduction(improving, depth, moveCount); - futilityValue = ss->staticEval + ss->evalMargin + futility_margin(predictedDepth, moveCount) - + Gains[pos.moved_piece(move)][to_sq(move)]; + predictedDepth = newDepth - reduction(improving, depth, moveCount); - if (futilityValue < beta) + // Futility pruning: parent node + if (predictedDepth < 7 * ONE_PLY) { - bestValue = std::max(bestValue, futilityValue); + futilityValue = ss->staticEval + futility_margin(predictedDepth) + + Value(128) + Gains[pos.moved_piece(move)][to_sq(move)]; - if (SpNode) + if (futilityValue <= alpha) { - splitPoint->mutex.lock(); - if (bestValue > splitPoint->bestValue) - splitPoint->bestValue = bestValue; + bestValue = std::max(bestValue, futilityValue); + + if (SpNode) + { + splitPoint->mutex.lock(); + if (bestValue > splitPoint->bestValue) + splitPoint->bestValue = bestValue; + } + continue; } - continue; } // Prune moves with negative SEE at low depths - if ( predictedDepth < 4 * ONE_PLY - && pos.see_sign(move) < 0) + if (predictedDepth < 4 * ONE_PLY && pos.see_sign(move) < 0) { if (SpNode) splitPoint->mutex.lock(); @@ -912,17 +890,12 @@ moves_loop: // When in check and at SpNode search starts from here continue; } - // We have not pruned the move that will be searched, but remember how - // far in the move list we are to be more aggressive in the child node. - ss->futilityMoveCount = moveCount; } - else - ss->futilityMoveCount = 0; // Check for legality only before to do the move if (!RootNode && !SpNode && !pos.legal(move, ci.pinned)) { - --moveCount; + moveCount--; continue; } @@ -1087,7 +1060,7 @@ moves_loop: // When in check and at SpNode search starts from here TT.store(posKey, value_to_tt(bestValue, ss->ply), bestValue >= beta ? BOUND_LOWER : PvNode && bestMove ? BOUND_EXACT : BOUND_UPPER, - depth, bestMove, ss->staticEval, ss->evalMargin); + depth, bestMove, ss->staticEval); // Quiet best move: update killers, history and countermoves if ( bestValue >= beta @@ -1180,7 +1153,7 @@ moves_loop: // When in check and at SpNode search starts from here // Evaluate the position statically if (InCheck) { - ss->staticEval = ss->evalMargin = VALUE_NONE; + ss->staticEval = VALUE_NONE; bestValue = futilityBase = -VALUE_INFINITE; } else @@ -1188,9 +1161,8 @@ moves_loop: // When in check and at SpNode search starts from here if (tte) { // Never assume anything on values stored in TT - if ( (ss->staticEval = bestValue = tte->eval_value()) == VALUE_NONE - ||(ss->evalMargin = tte->eval_margin()) == VALUE_NONE) - ss->staticEval = bestValue = evaluate(pos, ss->evalMargin); + if ((ss->staticEval = bestValue = tte->eval_value()) == VALUE_NONE) + ss->staticEval = bestValue = evaluate(pos); // Can ttValue be used as a better position evaluation? if (ttValue != VALUE_NONE) @@ -1198,14 +1170,14 @@ moves_loop: // When in check and at SpNode search starts from here bestValue = ttValue; } else - ss->staticEval = bestValue = evaluate(pos, ss->evalMargin); + ss->staticEval = bestValue = evaluate(pos); // Stand pat. Return immediately if static value is at least beta if (bestValue >= beta) { if (!tte) TT.store(pos.key(), value_to_tt(bestValue, ss->ply), BOUND_LOWER, - DEPTH_NONE, MOVE_NONE, ss->staticEval, ss->evalMargin); + DEPTH_NONE, MOVE_NONE, ss->staticEval); return bestValue; } @@ -1213,7 +1185,7 @@ moves_loop: // When in check and at SpNode search starts from here if (PvNode && bestValue > alpha) alpha = bestValue; - futilityBase = bestValue + ss->evalMargin + Value(128); + futilityBase = bestValue + Value(128); } // Initialize a MovePicker object for the current position, and prepare @@ -1302,7 +1274,7 @@ moves_loop: // When in check and at SpNode search starts from here else // Fail high { TT.store(posKey, value_to_tt(value, ss->ply), BOUND_LOWER, - ttDepth, move, ss->staticEval, ss->evalMargin); + ttDepth, move, ss->staticEval); return value; } @@ -1317,7 +1289,7 @@ moves_loop: // When in check and at SpNode search starts from here TT.store(posKey, value_to_tt(bestValue, ss->ply), PvNode && bestValue > oldAlpha ? BOUND_EXACT : BOUND_UPPER, - ttDepth, bestMove, ss->staticEval, ss->evalMargin); + ttDepth, bestMove, ss->staticEval); assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE); @@ -1371,7 +1343,7 @@ moves_loop: // When in check and at SpNode search starts from here // We exclude the trivial case where a sliding piece does in two moves what // it could do in one move: eg. Ra1a2, Ra2a3. if ( m2to == m1from - || (m1to == m2from && !squares_aligned(m1from, m2from, m2to))) + || (m1to == m2from && !aligned(m1from, m2from, m2to))) return true; // Second one moves through the square vacated by first one @@ -1556,7 +1528,7 @@ void RootMove::extract_pv_from_tt(Position& pos) { } while ( tte && pos.pseudo_legal(m = tte->move()) // Local copy, TT could change - && pos.legal(m, pos.pinned_pieces()) + && pos.legal(m, pos.pinned_pieces(pos.side_to_move())) && ply < MAX_PLY && (!pos.is_draw() || ply < 2)); @@ -1580,7 +1552,7 @@ void RootMove::insert_pv_in_tt(Position& pos) { tte = TT.probe(pos.key()); if (!tte || tte->move() != pv[ply]) // Don't overwrite correct entries - TT.store(pos.key(), VALUE_NONE, BOUND_NONE, DEPTH_NONE, pv[ply], VALUE_NONE, VALUE_NONE); + TT.store(pos.key(), VALUE_NONE, BOUND_NONE, DEPTH_NONE, pv[ply], VALUE_NONE); assert(MoveList(pos).contains(pv[ply])); @@ -1764,7 +1736,7 @@ void check_time() { && !Signals.failedLowAtRoot && elapsed > TimeMgr.available_time(); - bool noMoreTime = elapsed > TimeMgr.maximum_time() - 2 * TimerResolution + bool noMoreTime = elapsed > TimeMgr.maximum_time() - 2 * TimerThread::Resolution || stillAtFirstMove; if ( (Limits.use_time_management() && noMoreTime)