X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=a8b6e7d51d4d84650d1a65d76e39e246a6a8afdf;hp=fff9144d93152b1a7fd0469bdffa3d63877960c8;hb=38adb487ca37f276674d04e92dd3213f4d47cf72;hpb=8d858783e1bcf4266f30614c0f69677835976a22 diff --git a/src/search.cpp b/src/search.cpp index fff9144d..a8b6e7d5 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -127,6 +127,7 @@ namespace { }; EasyMoveManager EasyMove; + bool easyPlayed, failedLow; double BestMoveChanges; Value DrawValue[COLOR_NB]; CounterMovesHistoryStats CounterMovesHistory; @@ -141,6 +142,7 @@ namespace { Value value_from_tt(Value v, int ply); void update_pv(Move* pv, Move move, Move* childPv); void update_stats(const Position& pos, Stack* ss, Move move, Depth depth, Move* quiets, int quietsCnt); + void check_time(); } // namespace @@ -174,9 +176,9 @@ void Search::init() { } -/// Search::reset() clears all search memory, to obtain reproducible search results +/// Search::clear() resets to zero search state, to obtain reproducible results -void Search::reset () { +void Search::clear() { TT.clear(); CounterMovesHistory.clear(); @@ -216,14 +218,14 @@ uint64_t Search::perft(Position& pos, Depth depth) { return nodes; } -template uint64_t Search::perft(Position& pos, Depth depth); +template uint64_t Search::perft(Position&, Depth); -/// MainThread::think() is called by the main thread when the program receives +/// MainThread::search() is called by the main thread when the program receives /// the UCI 'go' command. It searches from root position and at the end prints /// the "bestmove" to output. -void MainThread::think() { +void MainThread::search() { Color us = rootPos.side_to_move(); Time.init(Limits, us, rootPos.game_ply()); @@ -289,28 +291,15 @@ void MainThread::think() { { th->maxPly = 0; th->rootDepth = DEPTH_ZERO; - th->searching = true; if (th != this) { th->rootPos = Position(rootPos, th); th->rootMoves = rootMoves; - th->notify_one(); // Wake up the thread and start searching + th->start_searching(); } } - Threads.timer->run = true; - Threads.timer->notify_one(); // Start the recurring timer - - search(true); // Let's start searching! - - // Stop the threads and the timer - Signals.stop = true; - Threads.timer->run = false; - - // Wait until all threads have finished - for (Thread* th : Threads) - if (th != this) - th->wait_while(th->searching); + Thread::search(); // Let's start searching! } // When playing in 'nodes as time' mode, subtract the searched nodes from @@ -329,10 +318,31 @@ void MainThread::think() { wait(Signals.stop); } - sync_cout << "bestmove " << UCI::move(rootMoves[0].pv[0], rootPos.is_chess960()); + // Stop the threads if not already stopped + Signals.stop = true; + + // Wait until all threads have finished + for (Thread* th : Threads) + if (th != this) + th->wait_for_search_finished(); + + // Check if there are threads with a better score than main thread. + Thread* bestThread = this; + if (!easyPlayed && Options["MultiPV"] == 1 && !Skill(Options["Skill Level"]).enabled()) + for (Thread* th : Threads) + if ( th->completedDepth > bestThread->completedDepth + && th->rootMoves[0].score > bestThread->rootMoves[0].score) + bestThread = th; + + // Send new PV when needed. + // FIXME: Breaks multiPV, and skill levels + if (bestThread != this) + sync_cout << UCI::pv(bestThread->rootPos, bestThread->completedDepth, -VALUE_INFINITE, VALUE_INFINITE) << sync_endl; - if (rootMoves[0].pv.size() > 1 || rootMoves[0].extract_ponder_from_tt(rootPos)) - std::cout << " ponder " << UCI::move(rootMoves[0].pv[1], rootPos.is_chess960()); + sync_cout << "bestmove " << UCI::move(bestThread->rootMoves[0].pv[0], rootPos.is_chess960()); + + if (bestThread->rootMoves[0].pv.size() > 1 || bestThread->rootMoves[0].extract_ponder_from_tt(rootPos)) + std::cout << " ponder " << UCI::move(bestThread->rootMoves[0].pv[1], rootPos.is_chess960()); std::cout << sync_endl; } @@ -342,21 +352,24 @@ void MainThread::think() { // repeatedly with increasing depth until the allocated thinking time has been // consumed, user stops the search, or the maximum search depth is reached. -void Thread::search(bool isMainThread) { +void Thread::search() { - Stack* ss = stack + 2; // To allow referencing (ss-2) and (ss+2) + Stack stack[MAX_PLY+4], *ss = stack+2; // To allow referencing (ss-2) and (ss+2) Value bestValue, alpha, beta, delta; Move easyMove = MOVE_NONE; + bool isMainThread = (this == Threads.main()); std::memset(ss-2, 0, 5 * sizeof(Stack)); bestValue = delta = alpha = -VALUE_INFINITE; beta = VALUE_INFINITE; + completedDepth = DEPTH_ZERO; if (isMainThread) { easyMove = EasyMove.get(rootPos.key()); EasyMove.clear(); + easyPlayed = false; BestMoveChanges = 0; TT.new_search(); } @@ -374,13 +387,33 @@ void Thread::search(bool isMainThread) { // Iterative deepening loop until requested to stop or target depth reached while (++rootDepth < DEPTH_MAX && !Signals.stop && (!Limits.depth || rootDepth <= Limits.depth)) { - // Set up the new depth for the helper threads + // Set up the new depth for the helper threads skipping in average each + // 2nd ply (using a half density map similar to a Hadamard matrix). if (!isMainThread) - rootDepth = Threads.main()->rootDepth + Depth(int(2.2 * log(1 + this->idx))); + { + int d = rootDepth + rootPos.game_ply(); + + if (idx <= 6 || idx > 24) + { + if (((d + idx) >> (msb(idx + 1) - 1)) % 2) + continue; + } + else + { + // Table of values of 6 bits with 3 of them set + static const int HalfDensityMap[] = { + 0x07, 0x0b, 0x0d, 0x0e, 0x13, 0x16, 0x19, 0x1a, 0x1c, + 0x23, 0x25, 0x26, 0x29, 0x2c, 0x31, 0x32, 0x34, 0x38 + }; + + if ((HalfDensityMap[idx - 7] >> (d % 6)) & 1) + continue; + } + } // Age out PV variability metric if (isMainThread) - BestMoveChanges *= 0.5; + BestMoveChanges *= 0.505, 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. @@ -441,7 +474,7 @@ void Thread::search(bool isMainThread) { if (isMainThread) { - Signals.failedLowAtRoot = true; + failedLow = true; Signals.stopOnPonderhit = false; } } @@ -472,6 +505,9 @@ void Thread::search(bool isMainThread) { sync_cout << UCI::pv(rootPos, rootDepth, alpha, beta) << sync_endl; } + if (!Signals.stop) + completedDepth = rootDepth; + if (!isMainThread) continue; @@ -498,10 +534,10 @@ void Thread::search(bool isMainThread) { // of the available time has been used or we matched an easyMove // from the previous search and just did a fast verification. if ( rootMoves.size() == 1 - || Time.elapsed() > Time.available() - || ( rootMoves[0].pv[0] == easyMove + || Time.elapsed() > Time.available() * (failedLow? 641 : 315)/640 + || ( easyPlayed = ( rootMoves[0].pv[0] == easyMove && BestMoveChanges < 0.03 - && Time.elapsed() > Time.available() / 10)) + && Time.elapsed() > Time.available() / 8))) { // If we are allowed to ponder do not stop the search now but // keep pondering until the GUI sends "ponderhit" or "stop". @@ -519,15 +555,12 @@ void Thread::search(bool isMainThread) { } } - searching = false; - notify_one(); // Wake up main thread if is sleeping waiting for us - if (!isMainThread) return; // Clear any candidate easy move that wasn't stable for the last search // iterations; the second condition prevents consecutive fast moves. - if (EasyMove.stableCnt < 6 || Time.elapsed() < Time.available()) + if (EasyMove.stableCnt < 6 || easyPlayed) EasyMove.clear(); // If skill level is enabled, swap best PV line with the sub-optimal one @@ -549,7 +582,7 @@ namespace { assert(-VALUE_INFINITE <= alpha && alpha < beta && beta <= VALUE_INFINITE); assert(PvNode || (alpha == beta - 1)); - assert(depth > DEPTH_ZERO); + assert(DEPTH_ZERO < depth && depth < DEPTH_MAX); Move pv[MAX_PLY+1], quietsSearched[64]; StateInfo st; @@ -569,6 +602,20 @@ namespace { bestValue = -VALUE_INFINITE; ss->ply = (ss-1)->ply + 1; + // Check for available remaining time + if (thisThread->resetCalls.load(std::memory_order_relaxed)) + { + thisThread->resetCalls = false; + thisThread->callsCnt = 0; + } + if (++thisThread->callsCnt > 4096) + { + for (Thread* th : Threads) + th->resetCalls = true; + + check_time(); + } + // Used to send selDepth info to GUI if (PvNode && thisThread->maxPly < ss->ply) thisThread->maxPly = ss->ply; @@ -577,7 +624,7 @@ namespace { { // Step 2. Check for aborted search and immediate draw if (Signals.stop.load(std::memory_order_relaxed) || pos.is_draw() || ss->ply >= MAX_PLY) - return ss->ply >= MAX_PLY && !inCheck ? evaluate(pos) + return ss->ply >= MAX_PLY && !inCheck ? evaluate(pos) : DrawValue[pos.side_to_move()]; // Step 3. Mate distance pruning. Even if we mate at the next move our score @@ -834,15 +881,10 @@ moves_loop: // When in check search starts from here ss->moveCount = ++moveCount; - if (RootNode && thisThread == Threads.main()) - { - Signals.firstRootMove = moveCount == 1; - - if (Time.elapsed() > 3000) - sync_cout << "info depth " << depth / ONE_PLY - << " currmove " << UCI::move(move, pos.is_chess960()) - << " currmovenumber " << moveCount + thisThread->PVIdx << sync_endl; - } + if (RootNode && thisThread == Threads.main() && Time.elapsed() > 3000) + sync_cout << "info depth " << depth / ONE_PLY + << " currmove " << UCI::move(move, pos.is_chess960()) + << " currmovenumber " << moveCount + thisThread->PVIdx << sync_endl; if (PvNode) (ss+1)->pv = nullptr; @@ -896,7 +938,8 @@ moves_loop: // When in check search starts from here continue; // History based pruning - if ( depth <= 3 * ONE_PLY + if ( depth <= 4 * ONE_PLY + && move != ss->killers[0] && thisThread->history[pos.moved_piece(move)][to_sq(move)] < VALUE_ZERO && cmh[pos.moved_piece(move)][to_sq(move)] < VALUE_ZERO) continue; @@ -1095,7 +1138,7 @@ moves_loop: // When in check search starts from here && is_ok((ss - 1)->currentMove) && is_ok((ss - 2)->currentMove)) { - Value bonus = Value((depth / ONE_PLY) * (depth / ONE_PLY)); + Value bonus = Value((depth / ONE_PLY) * (depth / ONE_PLY) + depth / ONE_PLY - 1); Square prevPrevSq = to_sq((ss - 2)->currentMove); CounterMovesStats& prevCmh = CounterMovesHistory[pos.piece_on(prevPrevSq)][prevPrevSq]; prevCmh.update(pos.piece_on(prevSq), prevSq, bonus); @@ -1359,8 +1402,8 @@ moves_loop: // When in check search starts from here } - // update_stats() updates killers, history, countermove history and - // countermoves stats for a quiet best move. + // update_stats() updates killers, history, countermove and countermove + // history when a new quiet best move is found. void update_stats(const Position& pos, Stack* ss, Move move, Depth depth, Move* quiets, int quietsCnt) { @@ -1371,7 +1414,7 @@ moves_loop: // When in check search starts from here ss->killers[0] = move; } - Value bonus = Value((depth / ONE_PLY) * (depth / ONE_PLY)); + Value bonus = Value((depth / ONE_PLY) * (depth / ONE_PLY) + depth / ONE_PLY - 1); Square prevSq = to_sq((ss-1)->currentMove); CounterMovesStats& cmh = CounterMovesHistory[pos.piece_on(prevSq)][prevSq]; @@ -1394,14 +1437,14 @@ moves_loop: // When in check search starts from here cmh.update(pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus); } - // Extra penalty for TT move in previous ply when it gets refuted + // Extra penalty for a quiet TT move in previous ply when it gets refuted if ( (ss-1)->moveCount == 1 && !pos.captured_piece_type() && is_ok((ss-2)->currentMove)) { Square prevPrevSq = to_sq((ss-2)->currentMove); CounterMovesStats& prevCmh = CounterMovesHistory[pos.piece_on(prevPrevSq)][prevPrevSq]; - prevCmh.update(pos.piece_on(prevSq), prevSq, -bonus - 2 * depth / ONE_PLY - 1); + prevCmh.update(pos.piece_on(prevSq), prevSq, -bonus - 2 * (depth + 1) / ONE_PLY); } } @@ -1411,23 +1454,23 @@ moves_loop: // When in check search starts from here Move Skill::pick_best(size_t multiPV) { - // PRNG sequence should be non-deterministic, so we seed it with the time at init const Search::RootMoveVector& rootMoves = Threads.main()->rootMoves; - static PRNG rng(now()); + static PRNG rng(now()); // PRNG sequence should be non-deterministic // RootMoves are already sorted by score in descending order - int variance = std::min(rootMoves[0].score - rootMoves[multiPV - 1].score, PawnValueMg); + Value topScore = rootMoves[0].score; + int delta = std::min(topScore - rootMoves[multiPV - 1].score, PawnValueMg); int weakness = 120 - 2 * level; int maxScore = -VALUE_INFINITE; - // Choose best move. For each move score we add two terms both dependent on + // Choose best move. For each move score we add two terms, both dependent on // weakness. One deterministic and bigger for weaker levels, and one random, // then we choose the move with the resulting highest score. for (size_t i = 0; i < multiPV; ++i) { // This is our magic formula - int push = ( weakness * int(rootMoves[0].score - rootMoves[i].score) - + variance * (rng.rand() % weakness)) / 128; + int push = ( weakness * int(topScore - rootMoves[i].score) + + delta * (rng.rand() % weakness)) / 128; if (rootMoves[i].score + push > maxScore) { @@ -1435,9 +1478,37 @@ moves_loop: // When in check search starts from here best = rootMoves[i].pv[0]; } } + return best; } + + // check_time() is used to print debug info and, more importantly, to detect + // when we are out of available time and thus stop the search. + + void check_time() { + + static TimePoint lastInfoTime = now(); + + int elapsed = Time.elapsed(); + TimePoint tick = Limits.startTime + elapsed; + + if (tick - lastInfoTime >= 1000) + { + lastInfoTime = tick; + dbg_print(); + } + + // An engine may not stop pondering until told so by the GUI + if (Limits.ponder) + return; + + if ( (Limits.use_time_management() && elapsed > Time.maximum() - 10) + || (Limits.movetime && elapsed >= Limits.movetime) + || (Limits.nodes && Threads.nodes_searched() >= Limits.nodes)) + Signals.stop = true; + } + } // namespace @@ -1512,7 +1583,8 @@ void RootMove::insert_pv_in_tt(Position& pos) { TTEntry* tte = TT.probe(pos.key(), ttHit); if (!ttHit || tte->move() != m) // Don't overwrite correct entries - tte->save(pos.key(), VALUE_NONE, BOUND_NONE, DEPTH_NONE, m, VALUE_NONE, TT.generation()); + tte->save(pos.key(), VALUE_NONE, BOUND_NONE, DEPTH_NONE, + m, VALUE_NONE, TT.generation()); pos.do_move(m, *st++, pos.gives_check(m, CheckInfo(pos))); } @@ -1522,10 +1594,10 @@ void RootMove::insert_pv_in_tt(Position& pos) { } -/// RootMove::extract_ponder_from_tt() is called in case we have no ponder move before -/// exiting the search, for instance in case we stop the search during a fail high at -/// root. We try hard to have a ponder move to return to the GUI, otherwise in case of -/// 'ponder on' we have nothing to think on. +/// RootMove::extract_ponder_from_tt() is called in case we have no ponder move +/// before exiting the search, for instance in case we stop the search during a +/// fail high at root. We try hard to have a ponder move to return to the GUI, +/// otherwise in case of 'ponder on' we have nothing to think on. bool RootMove::extract_ponder_from_tt(Position& pos) { @@ -1547,40 +1619,3 @@ bool RootMove::extract_ponder_from_tt(Position& pos) return false; } - - -/// check_time() is called by the timer thread when the timer triggers. It is -/// used to print debug info and, more importantly, to detect when we are out of -/// available time and thus stop the search. - -void check_time() { - - static TimePoint lastInfoTime = now(); - int elapsed = Time.elapsed(); - - if (now() - lastInfoTime >= 1000) - { - lastInfoTime = now(); - dbg_print(); - } - - // An engine may not stop pondering until told so by the GUI - if (Limits.ponder) - return; - - if (Limits.use_time_management()) - { - bool stillAtFirstMove = Signals.firstRootMove - && !Signals.failedLowAtRoot - && elapsed > Time.available() * 3 / 4; - - if ( stillAtFirstMove - || elapsed > Time.maximum() - 2 * TimerThread::Resolution) - Signals.stop = true; - } - else if (Limits.movetime && elapsed >= Limits.movetime) - Signals.stop = true; - - else if (Limits.nodes && Threads.nodes_searched() >= Limits.nodes) - Signals.stop = true; -}