X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=b0e2c950fe7354c784cd14689ab7c3cbb7bed6b4;hp=948f526cce836613e4e88fa80db9533ab9613c8e;hb=e51965aa57ddc50d04016e3622da49cf9f8e6238;hpb=13d4df95cd4c56c0e730328648de54d9ed8bd81e diff --git a/src/search.cpp b/src/search.cpp index 948f526c..b0e2c950 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -90,47 +90,48 @@ 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; @@ -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)); @@ -457,13 +460,13 @@ 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 +477,17 @@ 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 +585,7 @@ 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 @@ -1071,9 +1075,11 @@ 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; @@ -1396,8 +1402,8 @@ 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, countermoves and followupmoves + // 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) { @@ -1407,36 +1413,40 @@ moves_loop: // When in check and at SpNode search starts from here ss->killers[0] = move; } - // Increase history value of the cut-off move and decrease all the other - // played quiet moves. Value bonus = Value((depth / ONE_PLY) * (depth / ONE_PLY)); + + Square prevSq = to_sq((ss-1)->currentMove); + HistoryStats& cmh = CounterMovesHistory[pos.piece_on(prevSq)][prevSq]; + History.update(pos.moved_piece(move), to_sq(move), bonus); - for (int i = 0; i < quietsCnt; ++i) + if (is_ok((ss-1)->currentMove)) { - Move m = quiets[i]; - History.update(pos.moved_piece(m), to_sq(m), -bonus); + Countermoves.update(pos.piece_on(prevSq), prevSq, move); + cmh.update(pos.moved_piece(move), to_sq(move), bonus); } - if (is_ok((ss-1)->currentMove)) + // Decrease all the other played quiet moves + for (int i = 0; i < quietsCnt; ++i) { - Square prevMoveSq = to_sq((ss-1)->currentMove); - Piece prevMovePiece = pos.piece_on(prevMoveSq); - Countermoves.update(prevMovePiece, prevMoveSq, move); + History.update(pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus); - HistoryStats& cmh = CounterMovesHistory[prevMovePiece][prevMoveSq]; - cmh.update(pos.moved_piece(move), to_sq(move), bonus); - for (int i = 0; i < quietsCnt; ++i) - { - Move m = quiets[i]; - cmh.update(pos.moved_piece(m), to_sq(m), -bonus); - } + if (is_ok((ss-1)->currentMove)) + cmh.update(pos.moved_piece(quiets[i]), to_sq(quiets[i]), -bonus); } if (is_ok((ss-2)->currentMove) && (ss-1)->currentMove == (ss-1)->ttMove) { - Square prevOwnMoveSq = to_sq((ss-2)->currentMove); - Followupmoves.update(pos.piece_on(prevOwnMoveSq), prevOwnMoveSq, move); + Value bonus2 = Value(((depth+1) / ONE_PLY) * ((depth+1) / ONE_PLY)); + + Square prevPrevSq = to_sq((ss-2)->currentMove); + Followupmoves.update(pos.piece_on(prevPrevSq), prevPrevSq, move); + + Square prevMoveSq = to_sq((ss-1)->currentMove); + Piece prevMovePiece = pos.piece_on(prevMoveSq); + + HistoryStats& cmh2 = CounterMovesHistory[pos.piece_on(prevPrevSq)][prevPrevSq]; + cmh2.update(prevMovePiece, prevMoveSq, -bonus2); } } @@ -1595,34 +1605,17 @@ 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) { - mutex.lock(); + spinlock.acquire(); assert(activeSplitPoint); SplitPoint* sp = activeSplitPoint; - mutex.unlock(); + spinlock.release(); Stack stack[MAX_PLY+4], *ss = stack+2; // To allow referencing (ss-2) and (ss+2) Position pos(*sp->pos, this); @@ -1719,6 +1712,18 @@ 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 } }