X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=d75606ef02ab06a869c73244af95f64bd01f048a;hp=b08b687af2408f55d3690645963ae899db907fdd;hb=6c4257520847f7bb0f4008dedb65159cbacce106;hpb=2e8552db76092a7e4fa8f7278231d66e26a756d9 diff --git a/src/search.cpp b/src/search.cpp index b08b687a..d75606ef 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -90,53 +90,54 @@ namespace { Move best = MOVE_NONE; }; - struct FastMove { - FastMove() { clear(); } + // EasyMoveManager struct is used to detect a so called 'easy move'; when PV is + // stable across multiple search iterations we can fast return the best move. + struct EasyMoveManager { - inline void clear() { - expectedPosKey = 0; - pv3[0] = pv3[1] = pv3[2] = MOVE_NONE; + void clear() { stableCnt = 0; + expectedPosKey = 0; + pv[0] = pv[1] = pv[2] = MOVE_NONE; } - void update(Position& pos) { - // Keep track how many times in a row the PV stays stable 3 ply deep. - const std::vector& RMpv = RootMoves[0].pv; - if (RMpv.size() >= 3) - { - if (pv3[2] == RMpv[2]) - stableCnt++; - else - stableCnt = 0, pv3[2] = RMpv[2]; + Move get(Key key) const { + return expectedPosKey == key ? pv[2] : MOVE_NONE; + } - if (!expectedPosKey || pv3[0] != RMpv[0] || pv3[1] != RMpv[1]) - { - pv3[0] = RMpv[0], pv3[1] = RMpv[1]; - StateInfo st[2]; - pos.do_move(RMpv[0], st[0], pos.gives_check(RMpv[0], CheckInfo(pos))); - pos.do_move(RMpv[1], st[1], pos.gives_check(RMpv[1], CheckInfo(pos))); - expectedPosKey = pos.key(); - pos.undo_move(RMpv[1]); - pos.undo_move(RMpv[0]); - } + void update(Position& pos, const std::vector& newPv) { + + assert(newPv.size() >= 3); + + // Keep track of how many times in a row 3rd ply remains stable + stableCnt = (newPv[2] == pv[2]) ? stableCnt + 1 : 0; + + if (!std::equal(newPv.begin(), newPv.begin() + 3, pv)) + { + std::copy(newPv.begin(), newPv.begin() + 3, pv); + + StateInfo st[2]; + pos.do_move(newPv[0], st[0], pos.gives_check(newPv[0], CheckInfo(pos))); + pos.do_move(newPv[1], st[1], pos.gives_check(newPv[1], CheckInfo(pos))); + expectedPosKey = pos.key(); + pos.undo_move(newPv[1]); + pos.undo_move(newPv[0]); } - else - clear(); } - Key expectedPosKey; - Move pv3[3]; int stableCnt; - } FM; + Key expectedPosKey; + Move pv[3]; + }; size_t PVIdx; TimeManager TimeMgr; + EasyMoveManager EasyMove; double BestMoveChanges; Value DrawValue[COLOR_NB]; HistoryStats History; CounterMovesHistoryStats CounterMovesHistory; GainsStats Gains; - MovesStats Countermoves, Followupmoves; + MovesStats Countermoves; template Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth, bool cutNode); @@ -278,10 +279,13 @@ void Search::think() { } for (Thread* th : Threads) + { th->maxPly = 0; + th->notify_one(); // Wake up all the threads + } Threads.timer->run = true; - Threads.timer->notify_one(); // Wake up the recurring timer + Threads.timer->notify_one(); // Start the recurring timer id_loop(RootPos); // Let's start searching ! @@ -320,9 +324,8 @@ namespace { Depth depth; Value bestValue, alpha, beta, delta; - // Init fastMove if the previous search generated a candidate and we now got the predicted position. - const Move fastMove = (FM.expectedPosKey == pos.key()) ? FM.pv3[2] : MOVE_NONE; - FM.clear(); + Move easyMove = EasyMove.get(pos.key()); + EasyMove.clear(); std::memset(ss-2, 0, 5 * sizeof(Stack)); @@ -336,7 +339,6 @@ namespace { CounterMovesHistory.clear(); Gains.clear(); Countermoves.clear(); - Followupmoves.clear(); size_t multiPV = Options["MultiPV"]; Skill skill(Options["Skill Level"]); @@ -457,13 +459,13 @@ namespace { TimeMgr.pv_instability(BestMoveChanges); // Stop the search if only one legal move is available or all - // of the available time has been used or we matched a fastMove + // 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 || now() - SearchTime > TimeMgr.available_time() - || ( fastMove == RootMoves[0].pv[0] + || ( RootMoves[0].pv[0] == easyMove && BestMoveChanges < 0.03 - && 10 * (now() - SearchTime) > TimeMgr.available_time())) + && now() - SearchTime > TimeMgr.available_time() / 10)) { // If we are allowed to ponder do not stop the search now but // keep pondering until the GUI sends "ponderhit" or "stop". @@ -474,16 +476,17 @@ namespace { } } - // Update fast move stats. - FM.update(pos); + if (RootMoves[0].pv.size() >= 3) + EasyMove.update(pos, RootMoves[0].pv); + else + EasyMove.clear(); } } - // Clear any candidate fast move that wasn't completely stable for at least - // the 6 final search iterations. (Independent of actual depth and thus TC.) - // Time condition prevents consecutive fast moves. - if (FM.stableCnt < 6 || now() - SearchTime < TimeMgr.available_time()) - FM.clear(); + // 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 || now() - SearchTime < TimeMgr.available_time()) + EasyMove.clear(); // If skill level is enabled, swap best PV line with the sub-optimal one if (skill.enabled()) @@ -581,7 +584,7 @@ namespace { ss->ttMove = ttMove = RootNode ? RootMoves[PVIdx].pv[0] : ttHit ? tte->move() : MOVE_NONE; ttValue = ttHit ? value_from_tt(tte->value(), ss->ply) : VALUE_NONE; - // At non-PV nodes we check for a fail high/low. We don't probe at PV nodes + // At non-PV nodes we check for a fail high/low. We don't prune at PV nodes if ( !PvNode && ttHit && tte->depth() >= depth @@ -591,7 +594,7 @@ namespace { { ss->currentMove = ttMove; // Can be MOVE_NONE - // If ttMove is quiet, update killers, history, counter move and followup move on TT hit + // If ttMove is quiet, update killers, history, counter move on TT hit if (ttValue >= beta && ttMove && !pos.capture_or_promotion(ttMove) && !inCheck) update_stats(pos, ss, ttMove, depth, nullptr, 0); @@ -783,11 +786,7 @@ moves_loop: // When in check and at SpNode search starts from here Move countermoves[] = { Countermoves[pos.piece_on(prevMoveSq)][prevMoveSq].first, Countermoves[pos.piece_on(prevMoveSq)][prevMoveSq].second }; - Square prevOwnMoveSq = to_sq((ss-2)->currentMove); - Move followupmoves[] = { Followupmoves[pos.piece_on(prevOwnMoveSq)][prevOwnMoveSq].first, - Followupmoves[pos.piece_on(prevOwnMoveSq)][prevOwnMoveSq].second }; - - MovePicker mp(pos, ttMove, depth, History, CounterMovesHistory, countermoves, followupmoves, ss); + MovePicker mp(pos, ttMove, depth, History, CounterMovesHistory, countermoves, ss); CheckInfo ci(pos); value = bestValue; // Workaround a bogus 'uninitialized' warning under gcc improving = ss->staticEval >= (ss-2)->staticEval @@ -960,7 +959,10 @@ moves_loop: // When in check and at SpNode search starts from here ss->reduction = reduction(improving, depth, moveCount); if ( (!PvNode && cutNode) - || History[pos.piece_on(to_sq(move))][to_sq(move)] < VALUE_ZERO) + || History[pos.piece_on(to_sq(move))][to_sq(move)] < VALUE_ZERO + || ( History[pos.piece_on(to_sq(move))][to_sq(move)] + + CounterMovesHistory[pos.piece_on(prevMoveSq)][prevMoveSq] + [pos.piece_on(to_sq(move))][to_sq(move)] < VALUE_ZERO)) ss->reduction += ONE_PLY; if (move == countermoves[0] || move == countermoves[1]) @@ -1071,9 +1073,11 @@ moves_loop: // When in check and at SpNode search starts from here if (value > alpha) { - // Clear fast move if unstable. - if (PvNode && pos.key() == FM.expectedPosKey && (move != FM.pv3[2] || moveCount > 1)) - FM.clear(); + // If there is an easy move for this position, clear it if unstable + if ( PvNode + && EasyMove.get(pos.key()) + && (move != EasyMove.get(pos.key()) || moveCount > 1)) + EasyMove.clear(); bestMove = SpNode ? splitPoint->bestMove = move : move; @@ -1136,7 +1140,7 @@ moves_loop: // When in check and at SpNode search starts from here bestValue = excludedMove ? alpha : inCheck ? mated_in(ss->ply) : DrawValue[pos.side_to_move()]; - // Quiet best move: update killers, history, countermoves and followupmoves + // Quiet best move: update killers, history and countermoves else if (bestValue >= beta && !pos.capture_or_promotion(bestMove) && !inCheck) update_stats(pos, ss, bestMove, depth, quietsSearched, quietCount - 1); @@ -1396,8 +1400,8 @@ moves_loop: // When in check and at SpNode search starts from here *pv = MOVE_NONE; } - // update_stats() updates killers, history, countermoves and followupmoves - // stats after a fail-high of a quiet move. + // update_stats() updates killers, history and countermoves stats after a fail-high + // of a quiet move. void update_stats(const Position& pos, Stack* ss, Move move, Depth depth, Move* quiets, int quietsCnt) { @@ -1429,10 +1433,12 @@ moves_loop: // When in check and at SpNode 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 if (is_ok((ss-2)->currentMove) && (ss-1)->currentMove == (ss-1)->ttMove) { Square prevPrevSq = to_sq((ss-2)->currentMove); - Followupmoves.update(pos.piece_on(prevPrevSq), prevPrevSq, move); + HistoryStats& ttMoveCmh = CounterMovesHistory[pos.piece_on(prevPrevSq)][prevPrevSq]; + ttMoveCmh.update(pos.piece_on(prevSq), prevSq, -bonus - 2 * depth / ONE_PLY - 1); } } @@ -1591,25 +1597,8 @@ void Thread::idle_loop() { assert(!this_sp || (this_sp->master == this && searching)); - while ( !exit - && !(this_sp && this_sp->slavesMask.none())) + while (!exit && !(this_sp && this_sp->slavesMask.none())) { - // If there is nothing to do, sleep. - while( !exit - && !(this_sp && this_sp->slavesMask.none()) - && !searching) - { - if ( !this_sp - && !Threads.main()->thinking) - { - std::unique_lock lk(mutex); - while (!exit && !Threads.main()->thinking) - sleepCondition.wait(lk); - } - else - std::this_thread::yield(); - } - // If this thread has been assigned work, launch a search while (searching) { @@ -1715,6 +1704,18 @@ void Thread::idle_loop() { sp->spinlock.release(); } } + + // If search is finished then sleep, otherwise just yield + if (!Threads.main()->thinking) + { + assert(!this_sp); + + std::unique_lock lk(mutex); + while (!exit && !Threads.main()->thinking) + sleepCondition.wait(lk); + } + else + std::this_thread::yield(); // Wait for a new job or for our slaves to finish } }