X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=3c638ca057f5e1c3c515498e005cecf88a111c8e;hp=d59edbaeefcbf4be8ba40ea965156a21e0bf387a;hb=5410424e3d036b43715c7989aa99e449cdcde18e;hpb=2c237da54647bb7526f3512bea183eb44919cdda diff --git a/src/search.cpp b/src/search.cpp index d59edbae..3c638ca0 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -39,7 +39,6 @@ namespace Search { - SignalsType Signals; LimitsType Limits; } @@ -152,9 +151,8 @@ namespace { Value value_to_tt(Value v, int ply); Value value_from_tt(Value v, int ply); void update_pv(Move* pv, Move move, Move* childPv); - void update_cm_stats(Stack* ss, Piece pc, Square s, int bonus); + void update_continuation_histories(Stack* ss, Piece pc, Square to, int bonus); void update_stats(const Position& pos, Stack* ss, Move move, Move* quiets, int quietsCnt, int bonus); - void check_time(); } // namespace @@ -185,25 +183,28 @@ void Search::init() { } -/// Search::clear() resets search state to its initial value, to obtain reproducible results +/// Search::clear() resets search state to its initial value void Search::clear() { + Threads.main()->wait_for_search_finished(); + + Time.availableNodes = 0; TT.clear(); for (Thread* th : Threads) { - th->resetCalls = true; th->counterMoves.fill(MOVE_NONE); - th->history.fill(0); + th->mainHistory.fill(0); - for (auto& to : th->counterMoveHistory) + for (auto& to : th->contHistory) for (auto& h : to) h.fill(0); - th->counterMoveHistory[NO_PIECE][0].fill(CounterMovePruneThreshold - 1); + th->contHistory[NO_PIECE][0].fill(CounterMovePruneThreshold - 1); } + Threads.main()->callsCnt = 0; Threads.main()->previousScore = VALUE_INFINITE; } @@ -272,18 +273,18 @@ void MainThread::search() { Time.availableNodes += Limits.inc[us] - Threads.nodes_searched(); // When we reach the maximum depth, we can arrive here without a raise of - // Signals.stop. However, if we are pondering or in an infinite search, + // Threads.stop. However, if we are pondering or in an infinite search, // the UCI protocol states that we shouldn't print the best move before the // GUI sends a "stop" or "ponderhit" command. We therefore simply wait here - // until the GUI sends one of those commands (which also raises Signals.stop). - if (!Signals.stop && (Limits.ponder || Limits.infinite)) + // until the GUI sends one of those commands (which also raises Threads.stop). + if (!Threads.stop && (Threads.ponder || Limits.infinite)) { - Signals.stopOnPonderhit = true; - wait(Signals.stop); + Threads.stopOnPonderhit = true; + wait(Threads.stop); } // Stop the threads if not already stopped - Signals.stop = true; + Threads.stop = true; // Wait until all threads have finished for (Thread* th : Threads) @@ -336,7 +337,7 @@ void Thread::search() { std::memset(ss-4, 0, 7 * sizeof(Stack)); for (int i = 4; i > 0; i--) - (ss-i)->history = &this->counterMoveHistory[NO_PIECE][0]; // Use as sentinel + (ss-i)->contHistory = &this->contHistory[NO_PIECE][0]; // Use as sentinel bestValue = delta = alpha = -VALUE_INFINITE; beta = VALUE_INFINITE; @@ -362,8 +363,8 @@ void Thread::search() { // Iterative deepening loop until requested to stop or the target depth is reached while ( (rootDepth += ONE_PLY) < DEPTH_MAX - && !Signals.stop - && (!Limits.depth || Threads.main()->rootDepth / ONE_PLY <= Limits.depth)) + && !Threads.stop + && !(Limits.depth && mainThread && rootDepth / ONE_PLY > Limits.depth)) { // Distribute search depths across the threads if (idx) @@ -383,8 +384,11 @@ void Thread::search() { rm.previousScore = rm.score; // MultiPV loop. We perform a full root search for each PV line - for (PVIdx = 0; PVIdx < multiPV && !Signals.stop; ++PVIdx) + for (PVIdx = 0; PVIdx < multiPV && !Threads.stop; ++PVIdx) { + // Reset UCI info selDepth for each depth and each PV line + selDepth = 0; + // Reset aspiration window starting size if (rootDepth >= 5 * ONE_PLY) { @@ -411,7 +415,7 @@ void Thread::search() { // If search has been stopped, we break immediately. Sorting and // writing PV back to TT is safe because RootMoves is still // valid, although it refers to the previous iteration. - if (Signals.stop) + if (Threads.stop) break; // When failing high/low give some update (without cluttering @@ -432,14 +436,11 @@ void Thread::search() { if (mainThread) { mainThread->failedLow = true; - Signals.stopOnPonderhit = false; + Threads.stopOnPonderhit = false; } } else if (bestValue >= beta) - { - alpha = (alpha + beta) / 2; beta = std::min(bestValue + delta, VALUE_INFINITE); - } else break; @@ -454,11 +455,11 @@ void Thread::search() { if (!mainThread) continue; - if (Signals.stop || PVIdx + 1 == multiPV || Time.elapsed() > 3000) + if (Threads.stop || PVIdx + 1 == multiPV || Time.elapsed() > 3000) sync_cout << UCI::pv(rootPos, rootDepth, alpha, beta) << sync_endl; } - if (!Signals.stop) + if (!Threads.stop) completedDepth = rootDepth; if (!mainThread) @@ -472,12 +473,12 @@ void Thread::search() { if ( Limits.mate && bestValue >= VALUE_MATE_IN_MAX_PLY && VALUE_MATE - bestValue <= 2 * Limits.mate) - Signals.stop = true; + Threads.stop = true; // Do we have time for the next iteration? Can we stop searching now? if (Limits.use_time_management()) { - if (!Signals.stop && !Signals.stopOnPonderhit) + if (!Threads.stop && !Threads.stopOnPonderhit) { // Stop the search if only one legal move is available, or if all // of the available time has been used, or if we matched an easyMove @@ -498,10 +499,10 @@ void Thread::search() { { // If we are allowed to ponder do not stop the search now but // keep pondering until the GUI sends "ponderhit" or "stop". - if (Limits.ponder) - Signals.stopOnPonderhit = true; + if (Threads.ponder) + Threads.stopOnPonderhit = true; else - Signals.stop = true; + Threads.stop = true; } } @@ -551,8 +552,8 @@ namespace { Depth extension, newDepth; Value bestValue, value, ttValue, eval; bool ttHit, inCheck, givesCheck, singularExtensionNode, improving; - bool captureOrPromotion, doFullDepthSearch, moveCountPruning, skipQuiets; - Piece moved_piece; + bool captureOrPromotion, doFullDepthSearch, moveCountPruning, skipQuiets, ttCapture; + Piece movedPiece; int moveCount, quietCount; // Step 1. Initialize node @@ -564,32 +565,17 @@ namespace { ss->ply = (ss-1)->ply + 1; // Check for the available remaining time - if (thisThread->resetCalls.load(std::memory_order_relaxed)) - { - thisThread->resetCalls = false; - - // At low node count increase the checking rate to about 0.1% of nodes - // otherwise use a default value. - thisThread->callsCnt = Limits.nodes ? std::min(4096, int(Limits.nodes / 1024)) - : 4096; - } - - if (--thisThread->callsCnt <= 0) - { - for (Thread* th : Threads) - th->resetCalls = true; - - check_time(); - } + if (thisThread == Threads.main()) + static_cast(thisThread)->check_time(); // Used to send selDepth info to GUI - if (PvNode && thisThread->maxPly < ss->ply) - thisThread->maxPly = ss->ply; + if (PvNode && thisThread->selDepth < ss->ply) + thisThread->selDepth = ss->ply; if (!rootNode) { // Step 2. Check for aborted search and immediate draw - if (Signals.stop.load(std::memory_order_relaxed) || pos.is_draw(ss->ply) || ss->ply >= MAX_PLY) + if (Threads.stop.load(std::memory_order_relaxed) || pos.is_draw(ss->ply) || ss->ply >= MAX_PLY) return ss->ply >= MAX_PLY && !inCheck ? evaluate(pos) : DrawValue[pos.side_to_move()]; @@ -608,7 +594,7 @@ namespace { assert(0 <= ss->ply && ss->ply < MAX_PLY); ss->currentMove = (ss+1)->excludedMove = bestMove = MOVE_NONE; - ss->history = &thisThread->counterMoveHistory[NO_PIECE][0]; + ss->contHistory = &thisThread->contHistory[NO_PIECE][0]; (ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE; Square prevSq = to_sq((ss-1)->currentMove); @@ -640,14 +626,14 @@ namespace { // Extra penalty for a quiet TT move in previous ply when it gets refuted if ((ss-1)->moveCount == 1 && !pos.captured_piece()) - update_cm_stats(ss-1, pos.piece_on(prevSq), prevSq, -stat_bonus(depth + ONE_PLY)); + update_continuation_histories(ss-1, pos.piece_on(prevSq), prevSq, -stat_bonus(depth + ONE_PLY)); } // Penalty for a quiet ttMove that fails low else if (!pos.capture_or_promotion(ttMove)) { int penalty = -stat_bonus(depth); - thisThread->history.update(pos.side_to_move(), ttMove, penalty); - update_cm_stats(ss, pos.moved_piece(ttMove), to_sq(ttMove), penalty); + thisThread->mainHistory.update(pos.side_to_move(), ttMove, penalty); + update_continuation_histories(ss, pos.moved_piece(ttMove), to_sq(ttMove), penalty); } } return ttValue; @@ -668,7 +654,7 @@ namespace { if (err != TB::ProbeState::FAIL) { - thisThread->tbHits++; + thisThread->tbHits.fetch_add(1, std::memory_order_relaxed); int drawScore = TB::UseRule50 ? 1 : 0; @@ -699,9 +685,9 @@ namespace { eval = ss->staticEval = evaluate(pos); // Can ttValue be used as a better position evaluation? - if (ttValue != VALUE_NONE) - if (tte->bound() & (ttValue > eval ? BOUND_LOWER : BOUND_UPPER)) - eval = ttValue; + if ( ttValue != VALUE_NONE + && (tte->bound() & (ttValue > eval ? BOUND_LOWER : BOUND_UPPER))) + eval = ttValue; } else { @@ -751,7 +737,7 @@ namespace { Depth R = ((823 + 67 * depth / ONE_PLY) / 256 + std::min((eval - beta) / PawnValueMg, 3)) * ONE_PLY; ss->currentMove = MOVE_NULL; - ss->history = &thisThread->counterMoveHistory[NO_PIECE][0]; + ss->contHistory = &thisThread->contHistory[NO_PIECE][0]; pos.do_null_move(st); Value nullValue = depth-R < ONE_PLY ? -qsearch(pos, ss+1, -beta, -beta+1) @@ -793,7 +779,7 @@ namespace { if (pos.legal(move)) { ss->currentMove = move; - ss->history = &thisThread->counterMoveHistory[pos.moved_piece(move)][to_sq(move)]; + ss->contHistory = &thisThread->contHistory[pos.moved_piece(move)][to_sq(move)]; assert(depth >= 5 * ONE_PLY); pos.do_move(move, st); @@ -818,11 +804,10 @@ namespace { moves_loop: // When in check search starts from here - const PieceToHistory& cmh = *(ss-1)->history; - const PieceToHistory& fmh = *(ss-2)->history; - const PieceToHistory& fm2 = *(ss-4)->history; + const PieceToHistory* contHist[] = { (ss-1)->contHistory, (ss-2)->contHistory, nullptr, (ss-4)->contHistory }; + Move countermove = thisThread->counterMoves[pos.piece_on(prevSq)][prevSq]; - MovePicker mp(pos, ttMove, depth, ss); + MovePicker mp(pos, ttMove, depth, &thisThread->mainHistory, contHist, countermove, ss->killers); value = bestValue; // Workaround a bogus 'uninitialized' warning under gcc improving = ss->staticEval >= (ss-2)->staticEval /* || ss->staticEval == VALUE_NONE Already implicit in the previous condition */ @@ -836,6 +821,7 @@ moves_loop: // When in check search starts from here && (tte->bound() & BOUND_LOWER) && tte->depth() >= depth - 3 * ONE_PLY; skipQuiets = false; + ttCapture = false; // Step 11. Loop through moves // Loop through all pseudo-legal moves until no moves remain or a beta cutoff occurs @@ -865,7 +851,7 @@ moves_loop: // When in check search starts from here extension = DEPTH_ZERO; captureOrPromotion = pos.capture_or_promotion(move); - moved_piece = pos.moved_piece(move); + movedPiece = pos.moved_piece(move); givesCheck = type_of(move) == NORMAL && !pos.discovered_check_candidates() ? pos.check_squares(type_of(pos.piece_on(from_sq(move)))) & to_sq(move) @@ -923,8 +909,8 @@ moves_loop: // When in check search starts from here // Countermoves based pruning if ( lmrDepth < 3 - && (cmh[moved_piece][to_sq(move)] < CounterMovePruneThreshold) - && (fmh[moved_piece][to_sq(move)] < CounterMovePruneThreshold)) + && (*contHist[0])[movedPiece][to_sq(move)] < CounterMovePruneThreshold + && (*contHist[1])[movedPiece][to_sq(move)] < CounterMovePruneThreshold) continue; // Futility pruning: parent node @@ -954,9 +940,12 @@ moves_loop: // When in check search starts from here continue; } + if (move == ttMove && captureOrPromotion) + ttCapture = true; + // Update the current move (this must be done after singular extension search) ss->currentMove = move; - ss->history = &thisThread->counterMoveHistory[moved_piece][to_sq(move)]; + ss->contHistory = &thisThread->contHistory[movedPiece][to_sq(move)]; // Step 14. Make the move pos.do_move(move, st, givesCheck); @@ -973,6 +962,10 @@ moves_loop: // When in check search starts from here r -= r ? ONE_PLY : DEPTH_ZERO; else { + // Increase reduction if ttMove is a capture + if (ttCapture) + r += ONE_PLY; + // Increase reduction for cut nodes if (cutNode) r += 2 * ONE_PLY; @@ -984,11 +977,11 @@ moves_loop: // When in check search starts from here && !pos.see_ge(make_move(to_sq(move), from_sq(move)))) r -= 2 * ONE_PLY; - ss->statScore = cmh[moved_piece][to_sq(move)] - + fmh[moved_piece][to_sq(move)] - + fm2[moved_piece][to_sq(move)] - + thisThread->history[~pos.side_to_move()][from_to(move)] - - 4000; // Correction factor + ss->statScore = thisThread->mainHistory[~pos.side_to_move()][from_to(move)] + + (*contHist[0])[movedPiece][to_sq(move)] + + (*contHist[1])[movedPiece][to_sq(move)] + + (*contHist[3])[movedPiece][to_sq(move)] + - 4000; // Decrease/increase reduction by comparing opponent's stat score if (ss->statScore > 0 && (ss-1)->statScore < 0) @@ -1040,7 +1033,7 @@ moves_loop: // When in check search starts from here // Finished searching the move. If a stop occurred, the return value of // the search cannot be trusted, and we return immediately without // updating best move, PV and TT. - if (Signals.stop.load(std::memory_order_relaxed)) + if (Threads.stop.load(std::memory_order_relaxed)) return VALUE_ZERO; if (rootNode) @@ -1052,6 +1045,7 @@ moves_loop: // When in check search starts from here if (moveCount == 1 || value > alpha) { rm.score = value; + rm.selDepth = thisThread->selDepth; rm.pv.resize(1); assert((ss+1)->pv); @@ -1066,8 +1060,8 @@ moves_loop: // When in check search starts from here ++static_cast(thisThread)->bestMoveChanges; } else - // All other moves but the PV are set to the lowest value: this is - // not a problem when sorting because the sort is stable and the + // All other moves but the PV are set to the lowest value: this + // is not a problem when sorting because the sort is stable and the // move position in the list is preserved - just the PV is pushed up. rm.score = -VALUE_INFINITE; } @@ -1101,7 +1095,7 @@ moves_loop: // When in check search starts from here // completed. But in this case bestValue is valid because we have fully // searched our subtree, and we can anyhow save the result in TT. /* - if (Signals.stop) + if (Threads.stop) return VALUE_DRAW; */ @@ -1123,13 +1117,13 @@ moves_loop: // When in check search starts from here // Extra penalty for a quiet TT move in previous ply when it gets refuted if ((ss-1)->moveCount == 1 && !pos.captured_piece()) - update_cm_stats(ss-1, pos.piece_on(prevSq), prevSq, -stat_bonus(depth + ONE_PLY)); + 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 && !pos.captured_piece() && is_ok((ss-1)->currentMove)) - update_cm_stats(ss-1, pos.piece_on(prevSq), prevSq, stat_bonus(depth)); + update_continuation_histories(ss-1, pos.piece_on(prevSq), prevSq, stat_bonus(depth)); if (!excludedMove) tte->save(posKey, value_to_tt(bestValue, ss->ply), @@ -1220,9 +1214,9 @@ moves_loop: // When in check search starts from here ss->staticEval = bestValue = evaluate(pos); // Can ttValue be used as a better position evaluation? - if (ttValue != VALUE_NONE) - if (tte->bound() & (ttValue > bestValue ? BOUND_LOWER : BOUND_UPPER)) - bestValue = ttValue; + if ( ttValue != VALUE_NONE + && (tte->bound() & (ttValue > bestValue ? BOUND_LOWER : BOUND_UPPER))) + bestValue = ttValue; } else ss->staticEval = bestValue = @@ -1249,16 +1243,14 @@ moves_loop: // When in check search starts from here // to search the moves. Because the depth is <= 0 here, only captures, // queen promotions and checks (only if depth >= DEPTH_QS_CHECKS) will // be generated. - MovePicker mp(pos, ttMove, depth, to_sq((ss-1)->currentMove)); + const PieceToHistory* contHist[4] = {}; + MovePicker mp(pos, ttMove, depth, &pos.this_thread()->mainHistory, contHist, to_sq((ss-1)->currentMove)); // Loop through the moves until no moves remain or a beta cutoff occurs while ((move = mp.next_move()) != MOVE_NONE) { assert(is_ok(move)); - // Speculative prefetch as early as possible - prefetch(TT.first_entry(pos.key_after(move))); - givesCheck = type_of(move) == NORMAL && !pos.discovered_check_candidates() ? pos.check_squares(type_of(pos.piece_on(from_sq(move)))) & to_sq(move) : pos.gives_check(move); @@ -1300,6 +1292,9 @@ moves_loop: // When in check search starts from here && !pos.see_ge(move)) continue; + // Speculative prefetch as early as possible + prefetch(TT.first_entry(pos.key_after(move))); + // Check for legality just before making the move if (!pos.legal(move)) { @@ -1393,13 +1388,14 @@ moves_loop: // When in check search starts from here } - // update_cm_stats() updates countermove and follow-up move history + // update_continuation_histories() updates histories of the move pairs formed + // by moves at ply -1, -2, and -4 with current move. - void update_cm_stats(Stack* ss, Piece pc, Square s, int bonus) { + void update_continuation_histories(Stack* ss, Piece pc, Square to, int bonus) { for (int i : {1, 2, 4}) if (is_ok((ss-i)->currentMove)) - (ss-i)->history->update(pc, s, bonus); + (ss-i)->contHistory->update(pc, to, bonus); } @@ -1416,20 +1412,20 @@ moves_loop: // When in check search starts from here Color c = pos.side_to_move(); Thread* thisThread = pos.this_thread(); - thisThread->history.update(c, move, bonus); - update_cm_stats(ss, pos.moved_piece(move), to_sq(move), bonus); + thisThread->mainHistory.update(c, move, bonus); + update_continuation_histories(ss, pos.moved_piece(move), to_sq(move), bonus); if (is_ok((ss-1)->currentMove)) { Square prevSq = to_sq((ss-1)->currentMove); - thisThread->counterMoves[pos.piece_on(prevSq)][prevSq]=move; + thisThread->counterMoves[pos.piece_on(prevSq)][prevSq] = move; } // Decrease all the other played quiet moves for (int i = 0; i < quietsCnt; ++i) { - thisThread->history.update(c, quiets[i], -bonus); - update_cm_stats(ss, pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus); + thisThread->mainHistory.update(c, quiets[i], -bonus); + update_continuation_histories(ss, pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus); } } @@ -1467,11 +1463,19 @@ moves_loop: // When in check search starts from here return best; } +} // namespace // 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() { + void MainThread::check_time() { + + if (--callsCnt > 0) + return; + + // At low node count increase the checking rate to about 0.1% of nodes + // otherwise use a default value. + callsCnt = Limits.nodes ? std::min(4096, int(Limits.nodes / 1024)) : 4096; static TimePoint lastInfoTime = now(); @@ -1485,17 +1489,15 @@ moves_loop: // When in check search starts from here } // An engine may not stop pondering until told so by the GUI - if (Limits.ponder) + if (Threads.ponder) return; if ( (Limits.use_time_management() && elapsed > Time.maximum() - 10) || (Limits.movetime && elapsed >= Limits.movetime) || (Limits.nodes && Threads.nodes_searched() >= (uint64_t)Limits.nodes)) - Signals.stop = true; + Threads.stop = true; } -} // namespace - /// UCI::pv() formats PV information according to the UCI protocol. UCI requires /// that all (if any) unsearched PV lines are sent using a previous search score. @@ -1528,7 +1530,7 @@ string UCI::pv(const Position& pos, Depth depth, Value alpha, Value beta) { ss << "info" << " depth " << d / ONE_PLY - << " seldepth " << pos.this_thread()->maxPly + << " seldepth " << rootMoves[i].selDepth << " multipv " << i + 1 << " score " << UCI::value(v);