X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=17e54e4cd3cbedc32a9656f314fa8ac1514790f2;hp=3f8436415358e04840d4f54736446ae82efa7874;hb=f16c231bc9b239cc270e3103be93899f3204df76;hpb=e2880f9b8ea6f13cf845339798e738b0500abad8 diff --git a/src/search.cpp b/src/search.cpp index 3f843641..17e54e4c 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -82,7 +82,7 @@ namespace { bool thread_should_stop(int threadID) const; void wake_sleeping_threads(); void put_threads_to_sleep(); - void idle_loop(int threadID, SplitPoint* waitSp); + void idle_loop(int threadID, SplitPoint* sp); bool split(const Position& pos, SearchStack* ss, int ply, Value* alpha, const Value beta, Value* bestValue, Depth depth, bool mateThreat, int* moves, MovePicker* mp, int master, bool pvNode); @@ -232,7 +232,7 @@ namespace { const Value EasyMoveMargin = Value(0x200); // Last seconds noise filtering (LSN) - const bool UseLSNFiltering = false; + const bool UseLSNFiltering = true; const int LSNTime = 4000; // In milliseconds const Value LSNValue = value_from_centipawns(200); bool loseOnTime = false; @@ -294,7 +294,7 @@ namespace { Depth extension(const Position&, Move, bool, bool, bool, bool, bool, bool*); bool ok_to_do_nullmove(const Position& pos); bool ok_to_prune(const Position& pos, Move m, Move threat); - bool ok_to_use_TT(const TTEntry* tte, Depth depth, Value beta, int ply, bool allowNullmove); + bool ok_to_use_TT(const TTEntry* tte, Depth depth, Value beta, int ply); Value refine_eval(const TTEntry* tte, Value defaultEval, int ply); void update_history(const Position& pos, Move move, Depth depth, Move movesSearched[], int moveCount); void update_killers(Move m, SearchStack& ss); @@ -387,7 +387,7 @@ bool think(const Position& pos, bool infinite, bool ponder, int side_to_move, if (get_option_value_string("Book File") != OpeningBook.file_name()) OpeningBook.open(get_option_value_string("Book File")); - Move bookMove = OpeningBook.get_move(pos); + Move bookMove = OpeningBook.get_move(pos, get_option_value_bool("Best Book Move")); if (bookMove != MOVE_NONE) { if (PonderSearch) @@ -560,7 +560,7 @@ void init_search() { for (int j = 0; j < 64; j++) // j == moveNumber { // FIXME: test using log instead of BSR - FutilityMarginsMatrix[i][j] = (i < 2 ? 0 : 112 * bitScanReverse32(i * i / 2)) - 8 * j; + FutilityMarginsMatrix[i][j] = (i < 2 ? 0 : 112 * bitScanReverse32(i * i / 2)) - 8 * j + 45; } // Init futility move count array @@ -1299,8 +1299,11 @@ namespace { tte = TT.retrieve(posKey); ttMove = (tte ? tte->move() : MOVE_NONE); - if (tte && ok_to_use_TT(tte, depth, beta, ply, allowNullmove)) + if (tte && ok_to_use_TT(tte, depth, beta, ply)) { + // Refresh tte entry to avoid aging + TT.store(posKey, tte->value(), tte->type(), tte->depth(), ttMove); + ss[ply].currentMove = ttMove; // Can be MOVE_NONE return value_from_tt(tte->value(), ply); } @@ -1379,18 +1382,13 @@ namespace { if (nullValue >= value_mate_in(PLY_MAX)) nullValue = beta; - // Do zugzwang verification search for high depths, don't store in TT - // if search was stopped. - if ( ( depth < 6 * OnePly - || search(pos, ss, beta, depth-5*OnePly, ply, false, threadID) >= beta) - && !AbortSearch - && !TM.thread_should_stop(threadID)) - { - assert(value_to_tt(nullValue, ply) == nullValue); + if (depth < 6 * OnePly) + return nullValue; - TT.store(posKey, nullValue, VALUE_TYPE_NS_LO, depth, MOVE_NONE); + // Do zugzwang verification search + Value v = search(pos, ss, beta, depth-5*OnePly, ply, false, threadID); + if (v >= beta) return nullValue; - } } else { // The null move failed low, which means that we may be faced with // some kind of threat. If the previous move was reduced, check if @@ -1485,7 +1483,7 @@ namespace { // Value based pruning Depth predictedDepth = newDepth - nonpv_reduction(depth, moveCount); // We illogically ignore reduction condition depth >= 3*OnePly futilityValueScaled = ss[ply].eval + futility_margin(predictedDepth, moveCount) - + H.gain(pos.piece_on(move_from(move)), move_to(move)) + 45; + + H.gain(pos.piece_on(move_from(move)), move_to(move)); if (futilityValueScaled < beta) { @@ -1625,7 +1623,7 @@ namespace { tte = TT.retrieve(pos.get_key()); ttMove = (tte ? tte->move() : MOVE_NONE); - if (!pvNode && tte && ok_to_use_TT(tte, depth, beta, ply, true)) + if (!pvNode && tte && ok_to_use_TT(tte, depth, beta, ply)) { assert(tte->type() != VALUE_TYPE_EVAL); @@ -1712,7 +1710,7 @@ namespace { // Detect blocking evasions that are candidate to be pruned evasionPrunable = isCheck - && bestValue != -VALUE_INFINITE + && bestValue > value_mated_in(PLY_MAX) && !pos.move_is_capture(move) && pos.type_of_piece_on(move_from(move)) != KING && !pos.can_castle(pos.side_to_move()); @@ -1843,7 +1841,7 @@ namespace { // Value based pruning Depth predictedDepth = newDepth - nonpv_reduction(sp->depth, moveCount); futilityValueScaled = ss[sp->ply].eval + futility_margin(predictedDepth, moveCount) - + H.gain(pos.piece_on(move_from(move)), move_to(move)) + 45; + + H.gain(pos.piece_on(move_from(move)), move_to(move)); if (futilityValueScaled < sp->beta) { @@ -2306,18 +2304,14 @@ namespace { } - // ok_to_use_TT() returns true if a transposition table score can be used at a - // given point in search. To avoid zugzwang issues TT cutoffs at the root node - // of a null move verification search are not allowed if the TT value was found - // by a null search, this is implemented testing allowNullmove and TT entry type. + // ok_to_use_TT() returns true if a transposition table score + // can be used at a given point in search. - bool ok_to_use_TT(const TTEntry* tte, Depth depth, Value beta, int ply, bool allowNullmove) { + bool ok_to_use_TT(const TTEntry* tte, Depth depth, Value beta, int ply) { Value v = value_from_tt(tte->value(), ply); - return (allowNullmove || !(tte->type() & VALUE_TYPE_NULL)) - - && ( tte->depth() >= depth + return ( tte->depth() >= depth || v >= Max(value_mate_in(PLY_MAX), beta) || v < Min(value_mated_in(PLY_MAX), beta)) @@ -2642,10 +2636,10 @@ namespace { // idle_loop() is where the threads are parked when they have no work to do. - // The parameter "waitSp", if non-NULL, is a pointer to an active SplitPoint + // The parameter 'sp', if non-NULL, is a pointer to an active SplitPoint // object for which the current thread is the master. - void ThreadsManager::idle_loop(int threadID, SplitPoint* waitSp) { + void ThreadsManager::idle_loop(int threadID, SplitPoint* sp) { assert(threadID >= 0 && threadID < MAX_THREADS); @@ -2655,7 +2649,7 @@ namespace { // master should exit as last one. if (AllThreadsShouldExit) { - assert(!waitSp); + assert(!sp); threads[threadID].state = THREAD_TERMINATED; return; } @@ -2664,7 +2658,7 @@ namespace { // instead of wasting CPU time polling for work. while (AllThreadsShouldSleep || threadID >= ActiveThreads) { - assert(!waitSp); + assert(!sp); assert(threadID != 0); threads[threadID].state = THREAD_SLEEPING; @@ -2701,8 +2695,13 @@ namespace { // If this thread is the master of a split point and all threads have // finished their work at this split point, return from the idle loop. - if (waitSp != NULL && waitSp->cpus == 0) + if (sp && sp->cpus == 0) { + // Because sp->cpus is decremented under lock protection, + // be sure sp->lock has been released before to proceed. + lock_grab(&(sp->lock)); + lock_release(&(sp->lock)); + assert(threads[threadID].state == THREAD_AVAILABLE); threads[threadID].state = THREAD_SEARCHING; @@ -2773,7 +2772,7 @@ namespace { } // Wait until the thread has finished launching and is gone to sleep - while (threads[i].state != THREAD_SLEEPING); + while (threads[i].state != THREAD_SLEEPING) {} } } @@ -2814,7 +2813,7 @@ namespace { SplitPoint* sp; - for (sp = threads[threadID].splitPoint; sp && !sp->stopRequest; sp = sp->parent); + for (sp = threads[threadID].splitPoint; sp && !sp->stopRequest; sp = sp->parent) {} return sp != NULL; }