X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=163df7b4ec4b6f4f017fbe13318a0320a820c15e;hp=1cf9428ef43e47c5610e611350386877d2257edf;hb=4c91dbc28e8bb6265f80240de26b8e02f7020a51;hpb=b50ce5ebfbc9f8b043f0d915c47b0ac550d4affc diff --git a/src/search.cpp b/src/search.cpp index 1cf9428e..163df7b4 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -224,7 +224,7 @@ size_t Search::perft(Position& pos, Depth depth) { void Search::think() { - static Book book; // Defined static to initialize the PRNG only once + static PolyglotBook book; // Defined static to initialize the PRNG only once Position& pos = RootPosition; Chess960 = pos.is_chess960(); @@ -279,6 +279,8 @@ void Search::think() { // used to check for remaining available thinking time. if (Limits.use_time_management()) Threads.set_timer(std::min(100, std::max(TimeMgr.available_time() / 16, TimerResolution))); + else if (Limits.nodes) + Threads.set_timer(2 * TimerResolution); else Threads.set_timer(100); @@ -290,11 +292,11 @@ void Search::think() { if (Options["Use Search Log"]) { - int e = Time::now() - SearchTime; + Time::point elapsed = Time::now() - SearchTime + 1; Log log(Options["Search Log Filename"]); log << "Nodes: " << pos.nodes_searched() - << "\nNodes/second: " << (e > 0 ? pos.nodes_searched() * 1000 / e : 0) + << "\nNodes/second: " << pos.nodes_searched() * 1000 / elapsed << "\nBest move: " << move_to_san(pos, RootMoves[0].pv[0]); StateInfo st; @@ -365,7 +367,8 @@ namespace { // Start with a small aspiration window and, in case of fail high/low, // research with bigger window until not failing high/low anymore. - do { + while (true) + { // Search starts from ss+1 to allow referencing (ss-1). This is // needed by update gains and ss copy when splitting at Root. bestValue = search(pos, ss+1, alpha, beta, depth * ONE_PLY); @@ -419,9 +422,15 @@ namespace { else break; - assert(alpha >= -VALUE_INFINITE && beta <= VALUE_INFINITE); + // Search with full window in case we have a win/mate score + if (abs(bestValue) >= VALUE_KNOWN_WIN) + { + alpha = -VALUE_INFINITE; + beta = VALUE_INFINITE; + } - } while (abs(bestValue) < VALUE_KNOWN_WIN); + assert(alpha >= -VALUE_INFINITE && beta <= VALUE_INFINITE); + } } // Skills: Do we need to pick now the best move ? @@ -509,75 +518,65 @@ namespace { const bool RootNode = (NT == Root || NT == SplitPointRoot); assert(alpha >= -VALUE_INFINITE && alpha < beta && beta <= VALUE_INFINITE); - assert((alpha == beta - 1) || PvNode); + assert(PvNode || (alpha == beta - 1)); assert(depth > DEPTH_ZERO); Move movesSearched[64]; StateInfo st; const TTEntry *tte; + SplitPoint* sp; Key posKey; Move ttMove, move, excludedMove, bestMove, threatMove; Depth ext, newDepth; - Bound bt; Value bestValue, value, oldAlpha, ttValue; - Value refinedValue, nullValue, futilityBase, futilityValue; - bool isPvMove, inCheck, singularExtensionNode, givesCheck; + Value refinedValue, nullValue, futilityValue; + bool pvMove, inCheck, singularExtensionNode, givesCheck; bool captureOrPromotion, dangerous, doFullDepthSearch; - int moveCount = 0, playedMoveCount = 0; - Thread* thisThread = pos.this_thread(); - SplitPoint* sp = NULL; + int moveCount, playedMoveCount; - refinedValue = bestValue = value = -VALUE_INFINITE; + // Step 1. Initialize node + Thread* thisThread = pos.this_thread(); + moveCount = playedMoveCount = 0; oldAlpha = alpha; inCheck = pos.in_check(); - ss->ply = (ss-1)->ply + 1; - - // Used to send selDepth info to GUI - if (PvNode && thisThread->maxPly < ss->ply) - thisThread->maxPly = ss->ply; - // Step 1. Initialize node if (SpNode) { - tte = NULL; - ttMove = excludedMove = MOVE_NONE; - ttValue = VALUE_ZERO; sp = ss->sp; - bestMove = sp->bestMove; + bestMove = sp->bestMove; threatMove = sp->threatMove; - bestValue = sp->bestValue; - moveCount = sp->moveCount; // Lock must be held here + bestValue = sp->bestValue; + tte = NULL; + ttMove = excludedMove = MOVE_NONE; + ttValue = VALUE_NONE; - assert(bestValue > -VALUE_INFINITE && moveCount > 0); + assert(sp->bestValue > -VALUE_INFINITE && sp->moveCount > 0); goto split_point_start; } - else - { - ss->currentMove = threatMove = (ss+1)->excludedMove = bestMove = MOVE_NONE; - (ss+1)->skipNullMove = false; (ss+1)->reduction = DEPTH_ZERO; - (ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE; - - } - // Step 2. Check for aborted search and immediate draw - // Enforce node limit here. FIXME: This only works with 1 search thread. - if (Limits.nodes && pos.nodes_searched() >= Limits.nodes) - Signals.stop = true; + bestValue = -VALUE_INFINITE; + ss->currentMove = threatMove = (ss+1)->excludedMove = bestMove = MOVE_NONE; + ss->ply = (ss-1)->ply + 1; + (ss+1)->skipNullMove = false; (ss+1)->reduction = DEPTH_ZERO; + (ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE; - if (( Signals.stop - || pos.is_draw() - || ss->ply > MAX_PLY) && !RootNode) - return VALUE_DRAW; + // Used to send selDepth info to GUI + if (PvNode && thisThread->maxPly < ss->ply) + thisThread->maxPly = ss->ply; - // 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 - // a shorter mate was found upward in the tree then there is no need to search - // further, we will never beat current alpha. Same logic but with reversed signs - // applies also in the opposite condition of being mated instead of giving mate, - // in this case return a fail-high score. if (!RootNode) { + // Step 2. Check for aborted search and immediate draw + if (Signals.stop || pos.is_draw() || ss->ply > MAX_PLY) + return VALUE_DRAW; + + // 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 + // a shorter mate was found upward in the tree then there is no need to search + // further, we will never beat current alpha. Same logic but with reversed signs + // applies also in the opposite condition of being mated instead of giving mate, + // in this case return a fail-high score. alpha = std::max(mated_in(ss->ply), alpha); beta = std::min(mate_in(ss->ply+1), beta); if (alpha >= beta) @@ -591,7 +590,7 @@ namespace { posKey = excludedMove ? pos.exclusion_key() : pos.key(); tte = TT.probe(posKey); ttMove = RootNode ? RootMoves[PVIdx].pv[0] : tte ? tte->move() : MOVE_NONE; - ttValue = tte ? value_from_tt(tte->value(), ss->ply) : VALUE_ZERO; + ttValue = tte ? value_from_tt(tte->value(), ss->ply) : VALUE_NONE; // At PV nodes we check for exact scores, while at non-PV nodes we check for // a fail high/low. Biggest advantage at probing at PV nodes is to have a @@ -616,7 +615,7 @@ namespace { // Step 5. Evaluate the position statically and update parent's gain statistics if (inCheck) - ss->eval = ss->evalMargin = VALUE_NONE; + ss->eval = ss->evalMargin = refinedValue = VALUE_NONE; else if (tte) { assert(tte->static_value() != VALUE_NONE); @@ -784,7 +783,7 @@ split_point_start: // At split points actual search starts from here MovePicker mp(pos, ttMove, depth, H, ss, PvNode ? -VALUE_INFINITE : beta); CheckInfo ci(pos); - futilityBase = ss->eval + ss->evalMargin; + value = bestValue; // Workaround a bogus 'uninitialized' warning under gcc singularExtensionNode = !RootNode && !SpNode && depth >= SingularExtensionDepth[PvNode] @@ -811,12 +810,12 @@ split_point_start: // At split points actual search starts from here if (RootNode && !std::count(RootMoves.begin() + PVIdx, RootMoves.end(), move)) continue; - // At PV and SpNode nodes we want all moves to be legal since the beginning - if ((PvNode || SpNode) && !pos.pl_move_is_legal(move, ci.pinned)) - continue; - if (SpNode) { + // Shared counter cannot be decremented later if move turns out to be illegal + if (!pos.pl_move_is_legal(move, ci.pinned)) + continue; + moveCount = ++sp->moveCount; sp->mutex.unlock(); } @@ -833,7 +832,6 @@ split_point_start: // At split points actual search starts from here << " currmovenumber " << moveCount + PVIdx << sync_endl; } - isPvMove = (PvNode && moveCount <= 1); captureOrPromotion = pos.is_capture_or_promotion(move); givesCheck = pos.move_gives_check(move, ci); dangerous = givesCheck || is_dangerous(pos, move, captureOrPromotion); @@ -865,7 +863,7 @@ split_point_start: // At split points actual search starts from here ss->excludedMove = MOVE_NONE; if (value < rBeta) - ext = ONE_PLY; + ext = rBeta >= beta ? ONE_PLY + ONE_PLY / 2 : ONE_PLY; } // Update current move (this must be done after singular extension search) @@ -893,7 +891,7 @@ split_point_start: // At split points actual search starts from here // We illogically ignore reduction condition depth >= 3*ONE_PLY for predicted depth, // but fixing this made program slightly weaker. Depth predictedDepth = newDepth - reduction(depth, moveCount); - futilityValue = futilityBase + futility_margin(predictedDepth, moveCount) + futilityValue = ss->eval + ss->evalMargin + futility_margin(predictedDepth, moveCount) + H.gain(pos.piece_moved(move), to_sq(move)); if (futilityValue < beta) @@ -922,6 +920,7 @@ split_point_start: // At split points actual search starts from here continue; } + pvMove = PvNode ? moveCount == 1 : false; ss->currentMove = move; if (!SpNode && !captureOrPromotion && playedMoveCount < 64) movesSearched[playedMoveCount++] = move; @@ -932,7 +931,7 @@ split_point_start: // At split points actual search starts from here // Step 15. Reduced depth search (LMR). If the move fails high will be // re-searched at full depth. if ( depth > 3 * ONE_PLY - && !isPvMove + && !pvMove && !captureOrPromotion && !dangerous && ss->killers[0] != move @@ -948,7 +947,7 @@ split_point_start: // At split points actual search starts from here ss->reduction = DEPTH_ZERO; } else - doFullDepthSearch = !isPvMove; + doFullDepthSearch = !pvMove; // Step 16. Full depth search, when LMR is skipped or fails high if (doFullDepthSearch) @@ -961,7 +960,7 @@ split_point_start: // At split points actual search starts from here // Only for PV nodes do a full PV search on the first move or after a fail // high, in the latter case search only if value < beta, otherwise let the // parent node to fail low with value <= alpha and to try another move. - if (PvNode && (isPvMove || (value > alpha && (RootNode || value < beta)))) + if (PvNode && (pvMove || (value > alpha && (RootNode || value < beta)))) value = newDepth < ONE_PLY ? -qsearch(pos, ss+1, -beta, -alpha, DEPTH_ZERO) : - search(pos, ss+1, -beta, -alpha, newDepth); @@ -987,7 +986,7 @@ split_point_start: // At split points actual search starts from here RootMove& rm = *std::find(RootMoves.begin(), RootMoves.end(), move); // PV move or new best move ? - if (isPvMove || value > alpha) + if (pvMove || value > alpha) { rm.score = value; rm.extract_pv_from_tt(pos); @@ -995,7 +994,7 @@ split_point_start: // At split points actual search starts from here // We record how often the best move has been changed in each // iteration. This information is used for time management: When // the best move changes frequently, we allocate some more time. - if (!isPvMove && MultiPV == 1) + if (!pvMove && MultiPV == 1) BestMoveChanges++; } else @@ -1003,7 +1002,6 @@ split_point_start: // At split points actual search starts from here // is not a problem when sorting becuase sort is stable and move // position in the list is preserved, just the PV is pushed up. rm.score = -VALUE_INFINITE; - } if (value > bestValue) @@ -1014,15 +1012,17 @@ split_point_start: // At split points actual search starts from here if ( PvNode && value > alpha && value < beta) // We want always alpha < beta - alpha = value; + { + alpha = bestValue; // Update alpha here! + } if (SpNode && !thisThread->cutoff_occurred()) { - sp->bestValue = value; - sp->bestMove = move; + sp->bestValue = bestValue; + sp->bestMove = bestMove; sp->alpha = alpha; - if (value >= beta) + if (bestValue >= beta) sp->cutoff = true; } } @@ -1035,7 +1035,7 @@ split_point_start: // At split points actual search starts from here && !Signals.stop && !thisThread->cutoff_occurred()) bestValue = Threads.split(pos, ss, alpha, beta, bestValue, &bestMove, - depth, threatMove, moveCount, &mp, NT); + depth, threatMove, moveCount, mp, NT); } // Step 20. Check for mate and stalemate @@ -1044,41 +1044,42 @@ split_point_start: // At split points actual search starts from here // case of Signals.stop or thread.cutoff_occurred() are set, but this is // harmless because return value is discarded anyhow in the parent nodes. // If we are in a singular extension search then return a fail low score. - if (!moveCount) - return excludedMove ? oldAlpha : inCheck ? mated_in(ss->ply) : VALUE_DRAW; + // A split node has at least one move, the one tried before to be splitted. + if (!SpNode && !moveCount) + return excludedMove ? alpha : inCheck ? mated_in(ss->ply) : VALUE_DRAW; // If we have pruned all the moves without searching return a fail-low score if (bestValue == -VALUE_INFINITE) { assert(!playedMoveCount); - bestValue = oldAlpha; + bestValue = alpha; } // Step 21. Update tables // Update transposition table entry, killers and history if (!SpNode && !Signals.stop && !thisThread->cutoff_occurred()) { - move = bestValue <= oldAlpha ? MOVE_NONE : bestMove; - bt = bestValue <= oldAlpha ? BOUND_UPPER - : bestValue >= beta ? BOUND_LOWER : BOUND_EXACT; + Move ttm = bestValue <= oldAlpha ? MOVE_NONE : bestMove; + Bound bt = bestValue <= oldAlpha ? BOUND_UPPER + : bestValue >= beta ? BOUND_LOWER : BOUND_EXACT; - TT.store(posKey, value_to_tt(bestValue, ss->ply), bt, depth, move, ss->eval, ss->evalMargin); + TT.store(posKey, value_to_tt(bestValue, ss->ply), bt, depth, ttm, ss->eval, ss->evalMargin); // Update killers and history for non capture cut-off moves if ( bestValue >= beta - && !pos.is_capture_or_promotion(move) + && !pos.is_capture_or_promotion(bestMove) && !inCheck) { - if (move != ss->killers[0]) + if (bestMove != ss->killers[0]) { ss->killers[1] = ss->killers[0]; - ss->killers[0] = move; + ss->killers[0] = bestMove; } // Increase history value of the cut-off move Value bonus = Value(int(depth) * int(depth)); - H.add(pos.piece_moved(move), to_sq(move), bonus); + H.add(pos.piece_moved(bestMove), to_sq(bestMove), bonus); // Decrease history of all the other played non-capture moves for (int i = 0; i < playedMoveCount - 1; i++) @@ -1536,7 +1537,7 @@ split_point_start: // At split points actual search starts from here string uci_pv(const Position& pos, int depth, Value alpha, Value beta) { std::stringstream s; - int t = Time::now() - SearchTime; + Time::point elaspsed = Time::now() - SearchTime + 1; int selDepth = 0; for (size_t i = 0; i < Threads.size(); i++) @@ -1557,12 +1558,12 @@ split_point_start: // At split points actual search starts from here s << "\n"; s << "info depth " << d - << " seldepth " << selDepth - << " score " << (i == PVIdx ? score_to_uci(v, alpha, beta) : score_to_uci(v)) - << " nodes " << pos.nodes_searched() - << " nps " << (t > 0 ? pos.nodes_searched() * 1000 / t : 0) - << " time " << t - << " multipv " << i + 1 + << " seldepth " << selDepth + << " score " << (i == PVIdx ? score_to_uci(v, alpha, beta) : score_to_uci(v)) + << " nodes " << pos.nodes_searched() + << " nps " << pos.nodes_searched() * 1000 / elaspsed + << " time " << elaspsed + << " multipv " << i + 1 << " pv"; for (size_t j = 0; RootMoves[i].pv[j] != MOVE_NONE; j++) @@ -1708,6 +1709,10 @@ void Thread::idle_loop() { sp->mutex.lock(); + assert(sp->activePositions[idx] == NULL); + + sp->activePositions[idx] = &pos; + if (sp->nodeType == Root) search(pos, ss+1, sp->alpha, sp->beta, sp->depth); else if (sp->nodeType == PV) @@ -1720,6 +1725,7 @@ void Thread::idle_loop() { assert(is_searching); is_searching = false; + sp->activePositions[idx] = NULL; sp->slavesMask &= ~(1ULL << idx); sp->nodes += pos.nodes_searched(); @@ -1750,6 +1756,7 @@ void Thread::idle_loop() { void check_time() { static Time::point lastInfoTime = Time::now(); + int64_t nodes = 0; // Workaround silly 'uninitialized' gcc warning if (Time::now() - lastInfoTime >= 1000) { @@ -1760,15 +1767,45 @@ void check_time() { if (Limits.ponder) return; - int e = Time::now() - SearchTime; + if (Limits.nodes) + { + Threads.mutex.lock(); + + nodes = RootPosition.nodes_searched(); + + // Loop across all split points and sum accumulated SplitPoint nodes plus + // all the currently active slaves positions. + for (size_t i = 0; i < Threads.size(); i++) + for (int j = 0; j < Threads[i].splitPointsCnt; j++) + { + SplitPoint& sp = Threads[i].splitPoints[j]; + + sp.mutex.lock(); + + nodes += sp.nodes; + Bitboard sm = sp.slavesMask; + while (sm) + { + Position* pos = sp.activePositions[pop_lsb(&sm)]; + nodes += pos ? pos->nodes_searched() : 0; + } + + sp.mutex.unlock(); + } + + Threads.mutex.unlock(); + } + + Time::point elapsed = Time::now() - SearchTime; bool stillAtFirstMove = Signals.firstRootMove && !Signals.failedLowAtRoot - && e > TimeMgr.available_time(); + && elapsed > TimeMgr.available_time(); - bool noMoreTime = e > TimeMgr.maximum_time() - 2 * TimerResolution + bool noMoreTime = elapsed > TimeMgr.maximum_time() - 2 * TimerResolution || stillAtFirstMove; if ( (Limits.use_time_management() && noMoreTime) - || (Limits.movetime && e >= Limits.movetime)) + || (Limits.movetime && elapsed >= Limits.movetime) + || (Limits.nodes && nodes >= Limits.nodes)) Signals.stop = true; }