X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=1f848183481a573cf59710f2993a1c4fb890a1f2;hp=49074cee9c20d6a1bb9ff733394c7a966115d42e;hb=a90a990118fa84d1e6138654dd24d2f7f4ec3761;hpb=ba85c59d96d962dddaa0f1a2608ebea2e8ae694b diff --git a/src/search.cpp b/src/search.cpp index 49074cee..1f848183 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -363,7 +363,7 @@ int64_t perft(Position& pos, Depth depth) { bool think(Position& pos, const SearchLimits& limits, Move searchMoves[]) { - static Book book; + static Book book; // Define static to initialize the PRNG only once // Initialize global search-related variables StopOnPonderhit = StopRequest = QuitRequest = AspirationFailLow = false; @@ -409,9 +409,7 @@ bool think(Position& pos, const SearchLimits& limits, Move searchMoves[]) { read_evaluation_uci_options(pos.side_to_move()); Threads.read_uci_options(); - // Allocate pawn and material hash tables if number of active threads - // increased and set a new TT size if changed. - Threads.init_hash_tables(); + // Set a new TT size if changed TT.set_size(Options["Hash"].value()); if (Options["Clear Hash"].value()) @@ -536,8 +534,10 @@ namespace { Rml.bestMoveChanges = 0; - // MultiPV iteration loop - for (MultiPVIteration = 0; MultiPVIteration < Min(MultiPV, (int)Rml.size()); MultiPVIteration++) + // MultiPV iteration loop. At depth 1 perform at least 2 iterations to + // get a score of the second best move for easy move detection. + int e = Min(Max(MultiPV, 2 * int(depth == 1)), (int)Rml.size()); + for (MultiPVIteration = 0; MultiPVIteration < e; MultiPVIteration++) { // Calculate dynamic aspiration window based on previous iterations if (depth >= 5 && abs(Rml[MultiPVIteration].prevScore) < VALUE_KNOWN_WIN) @@ -780,8 +780,18 @@ namespace { : can_return_tt(tte, depth, beta, ss->ply))) { TT.refresh(tte); - ss->bestMove = ttMove; // Can be MOVE_NONE - return value_from_tt(tte->value(), ss->ply); + ss->bestMove = move = ttMove; // Can be MOVE_NONE + value = value_from_tt(tte->value(), ss->ply); + + if ( value >= beta + && move + && !pos.move_is_capture_or_promotion(move) + && move != ss->killers[0]) + { + ss->killers[1] = ss->killers[0]; + ss->killers[0] = move; + } + return value; } // Step 5. Evaluate the position statically and update parent's gain statistics @@ -1002,8 +1012,7 @@ split_point_start: // At split points actual search starts from here << " currmovenumber " << moveCount + MultiPVIteration << endl; } - // At Root and at first iteration do a PV search on all the moves to score root moves - isPvMove = (PvNode && moveCount <= (RootNode && depth <= ONE_PLY ? MAX_MOVES : 1)); + isPvMove = (PvNode && moveCount == 1); givesCheck = pos.move_gives_check(move, ci); captureOrPromotion = pos.move_is_capture_or_promotion(move); @@ -1540,8 +1549,8 @@ split_point_start: // At split points actual search starts from here Piece p1, p2; Square ksq; - assert(m1 && move_is_ok(m1)); - assert(m2 && move_is_ok(m2)); + assert(move_is_ok(m1)); + assert(move_is_ok(m2)); // Case 1: The moving piece is the same in both moves f2 = move_from(m2); @@ -1617,7 +1626,7 @@ split_point_start: // At split points actual search starts from here bool connected_threat(const Position& pos, Move m, Move threat) { assert(move_is_ok(m)); - assert(threat && move_is_ok(threat)); + assert(move_is_ok(threat)); assert(!pos.move_is_capture_or_promotion(m)); assert(!pos.move_is_passed_pawn_push(m)); @@ -2130,13 +2139,11 @@ split_point_start: // At split points actual search starts from here } // namespace -// Little helper used by idle_loop() to check that all the slaves of a -// master thread have finished searching. +// Little helper used by idle_loop() to check that all the slave threads of a +// split point have finished searching. static bool all_slaves_finished(SplitPoint* sp) { - assert(sp); - for (int i = 0; i < Threads.size(); i++) if (sp->is_slave[i]) return false; @@ -2157,22 +2164,17 @@ void Thread::idle_loop(SplitPoint* sp) { // instead of wasting CPU time polling for work. while ( do_sleep || do_terminate - || (Threads.use_sleeping_threads() && state == Thread::AVAILABLE)) + || (Threads.use_sleeping_threads() && !is_searching)) { - assert(!sp || Threads.use_sleeping_threads()); - assert(threadID != 0 || Threads.use_sleeping_threads()); + assert((!sp && threadID) || Threads.use_sleeping_threads()); // Slave thread should exit as soon as do_terminate flag raises if (do_terminate) { assert(!sp); - state = Thread::TERMINATED; return; } - if (state == Thread::INITIALIZING) - state = Thread::AVAILABLE; - // Grab the lock to avoid races with Thread::wake_up() lock_grab(&sleepLock); @@ -2187,19 +2189,17 @@ void Thread::idle_loop(SplitPoint* sp) { // particular we need to avoid a deadlock in case a master thread has, // in the meanwhile, allocated us and sent the wake_up() call before we // had the chance to grab the lock. - if (do_sleep || state == Thread::AVAILABLE) + if (do_sleep || !is_searching) cond_wait(&sleepCond, &sleepLock); lock_release(&sleepLock); } // If this thread has been assigned work, launch a search - if (state == Thread::WORKISWAITING) + if (is_searching) { assert(!do_terminate); - state = Thread::SEARCHING; - // Copy split point position and search stack and call search() SearchStack ss[PLY_MAX_PLUS_2]; SplitPoint* tsp = splitPoint; @@ -2217,15 +2217,15 @@ void Thread::idle_loop(SplitPoint* sp) { else assert(false); - assert(state == Thread::SEARCHING); + assert(is_searching); - state = Thread::AVAILABLE; + is_searching = false; // Wake up master thread so to allow it to return from the idle loop in // case we are the last slave of the split point. if ( Threads.use_sleeping_threads() && threadID != tsp->master - && Threads[tsp->master].state == Thread::AVAILABLE) + && !Threads[tsp->master].is_searching) Threads[tsp->master].wake_up(); }