X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=03c566ebf29970f77f37d20991794314558ea650;hp=d54087b966e35c5ef09a131f48e3932d8657d12e;hb=b870f5a091793ea423de78e74f5652b9307cfcbd;hpb=c6630abe0d6f229af7d6ae788643a0e8fa1737f7 diff --git a/src/search.cpp b/src/search.cpp index d54087b9..03c566eb 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -125,9 +125,6 @@ namespace { const bool UseIIDAtPVNodes = true; const bool UseIIDAtNonPVNodes = false; - // Use null move driven internal iterative deepening? - bool UseNullDrivenIID = false; - // Internal iterative deepening margin. At Non-PV moves, when // UseIIDAtNonPVNodes is true, we do an internal iterative deepening search // when the static evaluation is at most IIDMargin below beta. @@ -196,7 +193,6 @@ namespace { // Iteration counters int Iteration; - bool LastIterations; BetaCounterType BetaCounter; // Scores and number of times the best move changed for each iteration: @@ -210,7 +206,7 @@ namespace { int SearchStartTime; int MaxNodes, MaxDepth; int MaxSearchTime, AbsoluteMaxSearchTime, ExtraSearchTime; - Move BestRootMove, PonderMove, EasyMove; + Move EasyMove; int RootMoveNumber; bool InfiniteSearch; bool PonderSearch; @@ -259,8 +255,6 @@ namespace { Depth depth, int ply, int threadID); void sp_search(SplitPoint *sp, int threadID); void sp_search_pv(SplitPoint *sp, int threadID); - void init_search_stack(SearchStack& ss); - void init_search_stack(SearchStack ss[]); void init_node(const Position &pos, SearchStack ss[], int ply, int threadID); void update_pv(SearchStack ss[], int ply); void sp_update_pv(SearchStack *pss, SearchStack ss[], int ply); @@ -290,9 +284,8 @@ namespace { bool thread_is_available(int slave, int master); bool idle_thread_exists(int master); bool split(const Position &pos, SearchStack *ss, int ply, - Value *alpha, Value *beta, Value *bestValue, Depth depth, - int *moves, MovePicker *mp, Bitboard dcCandidates, int master, - bool pvNode); + Value *alpha, Value *beta, Value *bestValue, Depth depth, int *moves, + MovePicker *mp, Bitboard dcCandidates, int master, bool pvNode); void wake_sleeping_threads(); #if !defined(_MSC_VER) @@ -325,6 +318,24 @@ History H; // Should be made local? SearchStack EmptySearchStack; +// SearchStack::init() initializes a search stack. Used at the beginning of a +// new search from the root. +void SearchStack::init(int ply) { + + pv[ply] = pv[ply + 1] = MOVE_NONE; + currentMove = threatMove = MOVE_NONE; + reduction = Depth(0); + currentMoveCaptureValue = Value(0); +} + +void SearchStack::initKillers() { + + mateKiller = MOVE_NONE; + for (int i = 0; i < KILLER_MAX; i++) + killers[i] = MOVE_NONE; +} + + //// //// Functions //// @@ -357,8 +368,6 @@ void think(const Position &pos, bool infinite, bool ponder, int side_to_move, // Initialize global search variables Idle = false; SearchStartTime = get_system_time(); - BestRootMove = MOVE_NONE; - PonderMove = MOVE_NONE; EasyMove = MOVE_NONE; for (int i = 0; i < THREAD_MAX; i++) { @@ -412,7 +421,6 @@ void think(const Position &pos, bool infinite, bool ponder, int side_to_move, if (UseLogFile) LogFile.open(get_option_value_string("Search Log Filename").c_str(), std::ios::out | std::ios::app); - UseNullDrivenIID = get_option_value_bool("Null driven IID"); UseQSearchFutilityPruning = get_option_value_bool("Futility Pruning (Quiescence Search)"); UseFutilityPruning = get_option_value_bool("Futility Pruning (Main Search)"); @@ -589,7 +597,8 @@ void init_threads() { } // Init also the empty search stack - init_search_stack(EmptySearchStack); + EmptySearchStack.init(0); + EmptySearchStack.initKillers(); } @@ -641,12 +650,14 @@ namespace { // Initialize TT.new_search(); H.clear(); - init_search_stack(ss); - + for (int i = 0; i < 3; i++) + { + ss[i].init(i); + ss[i].initKillers(); + } ValueByIteration[0] = Value(0); ValueByIteration[1] = rml.get_move_score(0); Iteration = 1; - LastIterations = false; EasyMove = rml.scan_for_easy_move(); @@ -701,9 +712,6 @@ namespace { ExtraSearchTime = BestMoveChangesByIteration[Iteration] * (MaxSearchTime / 2) + BestMoveChangesByIteration[Iteration-1] * (MaxSearchTime / 3); - // Try to guess if the current iteration is the last one or the last two - LastIterations = (current_search_time() > ((MaxSearchTime + ExtraSearchTime)*58) / 128); - // Stop search if most of MaxSearchTime is consumed at the end of the // iteration. We probably don't have enough time to search the first // move at the next iteration anyway. @@ -754,12 +762,12 @@ namespace { if (dbg_show_hit_rate) dbg_print_hit_rate(LogFile); - UndoInfo u; + StateInfo st; LogFile << "Nodes: " << nodes_searched() << std::endl << "Nodes/second: " << nps() << std::endl << "Best move: " << move_to_san(p, ss[0].pv[0]) << std::endl; - p.do_move(ss[0].pv[0], u); + p.do_move(ss[0].pv[0], st); LogFile << "Ponder move: " << move_to_san(p, ss[0].pv[1]) << std::endl << std::endl; } @@ -783,7 +791,7 @@ namespace { { int64_t nodes; Move move; - UndoInfo u; + StateInfo st; Depth ext, newDepth; RootMoveNumber = i + 1; @@ -809,7 +817,7 @@ namespace { newDepth = (Iteration - 2) * OnePly + ext + InitialDepth; // Make the move, and search it - pos.do_move(move, u, dcCandidates); + pos.do_move(move, st, dcCandidates); if (i < MultiPV) { @@ -837,7 +845,7 @@ namespace { } } - pos.undo_move(move, u); + pos.undo_move(move); // Finished searching the move. If AbortSearch is true, the search // was aborted because the user interrupted the search or because we @@ -984,8 +992,9 @@ namespace { int moveCount = 0; Value value, bestValue = -VALUE_INFINITE; Bitboard dcCandidates = mp.discovered_check_candidates(); + Color us = pos.side_to_move(); bool isCheck = pos.is_check(); - bool mateThreat = pos.has_mate_threat(opposite_color(pos.side_to_move())); + bool mateThreat = pos.has_mate_threat(opposite_color(us)); // Loop through all legal moves until no moves remain or a beta cutoff // occurs. @@ -996,7 +1005,7 @@ namespace { assert(move_is_ok(move)); bool singleReply = (isCheck && mp.number_of_moves() == 1); - bool moveIsCheck = pos.move_is_check(move); + bool moveIsCheck = pos.move_is_check(move, dcCandidates); bool moveIsCapture = pos.move_is_capture(move); movesSearched[moveCount++] = ss[ply].currentMove = move; @@ -1013,8 +1022,8 @@ namespace { Depth newDepth = depth - OnePly + ext; // Make and search the move - UndoInfo u; - pos.do_move(move, u, dcCandidates); + StateInfo st; + pos.do_move(move, st, dcCandidates); if (moveCount == 1) // The first move in list is the PV value = -search_pv(pos, ss, -beta, -alpha, newDepth, ply+1, threadID); @@ -1056,7 +1065,7 @@ namespace { } } } - pos.undo_move(move, u); + pos.undo_move(move); assert(value > -VALUE_INFINITE && value < VALUE_INFINITE); @@ -1171,7 +1180,6 @@ namespace { Value approximateEval = quick_evaluate(pos); bool mateThreat = false; - bool nullDrivenIID = false; bool isCheck = pos.is_check(); // Null move search @@ -1184,26 +1192,13 @@ namespace { { ss[ply].currentMove = MOVE_NULL; - UndoInfo u; - pos.do_null_move(u); + StateInfo st; + pos.do_null_move(st); int R = (depth >= 4 * OnePly ? 4 : 3); // Null move dynamic reduction Value nullValue = -search(pos, ss, -(beta-1), depth-R*OnePly, ply+1, false, threadID); - // Check for a null capture artifact, if the value without the null capture - // is above beta then mark the node as a suspicious failed low. We will verify - // later if we are really under threat. - if ( UseNullDrivenIID - && nullValue < beta - && depth > 6 * OnePly - &&!value_is_mate(nullValue) - && ttMove == MOVE_NONE - && ss[ply + 1].currentMove != MOVE_NONE - && pos.move_is_capture(ss[ply + 1].currentMove) - && pos.see(ss[ply + 1].currentMove) + nullValue >= beta) - nullDrivenIID = true; - - pos.undo_null_move(u); + pos.undo_null_move(); if (value_is_mate(nullValue)) { @@ -1226,10 +1221,8 @@ namespace { // low score (which will cause the reduced move to fail high in the // parent node, which will trigger a re-search with full depth). if (nullValue == value_mated_in(ply + 2)) - { mateThreat = true; - nullDrivenIID = false; - } + ss[ply].threatMove = ss[ply + 1].currentMove; if ( depth < ThreatDepth && ss[ply - 1].reduction @@ -1259,22 +1252,6 @@ namespace { search(pos, ss, beta, Min(depth/2, depth-2*OnePly), ply, false, threadID); ttMove = ss[ply].pv[ply]; } - else if (nullDrivenIID) - { - // The null move failed low due to a suspicious capture. Perhaps we - // are facing a null capture artifact due to the side to move change - // and this position should fail high. So do a normal search with a - // reduced depth to get a good ttMove to use in the following full - // depth search. - Move tm = ss[ply].threatMove; - - assert(tm != MOVE_NONE); - assert(ttMove == MOVE_NONE); - - search(pos, ss, beta, depth/2, ply, false, threadID); - ttMove = ss[ply].pv[ply]; - ss[ply].threatMove = tm; - } // Initialize a MovePicker object for the current position, and prepare // to search all moves: @@ -1298,7 +1275,7 @@ namespace { assert(move_is_ok(move)); bool singleReply = (isCheck && mp.number_of_moves() == 1); - bool moveIsCheck = pos.move_is_check(move); + bool moveIsCheck = pos.move_is_check(move, dcCandidates); bool moveIsCapture = pos.move_is_capture(move); movesSearched[moveCount++] = ss[ply].currentMove = move; @@ -1337,8 +1314,8 @@ namespace { } // Make and search the move - UndoInfo u; - pos.do_move(move, u, dcCandidates); + StateInfo st; + pos.do_move(move, st, dcCandidates); // Try to reduce non-pv search depth by one ply if move seems not problematic, // if the move fails high will be re-searched at full depth. @@ -1361,7 +1338,7 @@ namespace { ss[ply].reduction = Depth(0); value = -search(pos, ss, -(beta-1), newDepth, ply+1, true, threadID); } - pos.undo_move(move, u); + pos.undo_move(move); assert(value > -VALUE_INFINITE && value < VALUE_INFINITE); @@ -1471,7 +1448,8 @@ namespace { Move move; int moveCount = 0; Bitboard dcCandidates = mp.discovered_check_candidates(); - bool enoughMaterial = pos.non_pawn_material(pos.side_to_move()) > RookValueMidgame; + Color us = pos.side_to_move(); + bool enoughMaterial = pos.non_pawn_material(us) > RookValueMidgame; // Loop through the moves until no moves remain or a beta cutoff // occurs. @@ -1489,7 +1467,7 @@ namespace { && !isCheck && !pvNode && !move_promotion(move) - && !pos.move_is_check(move) + && !pos.move_is_check(move, dcCandidates) && !pos.move_is_passed_pawn_push(move)) { Value futilityValue = staticValue @@ -1516,10 +1494,10 @@ namespace { continue; // Make and search the move. - UndoInfo u; - pos.do_move(move, u, dcCandidates); + StateInfo st; + pos.do_move(move, st, dcCandidates); Value value = -qsearch(pos, ss, -beta, -alpha, depth-OnePly, ply+1, threadID); - pos.undo_move(move, u); + pos.undo_move(move); assert(value > -VALUE_INFINITE && value < VALUE_INFINITE); @@ -1583,9 +1561,8 @@ namespace { && (move = sp->mp->get_next_move(sp->lock)) != MOVE_NONE) { assert(move_is_ok(move)); - assert(pos.discovered_check_candidates(pos.side_to_move()) == sp->dcCandidates); - bool moveIsCheck = pos.move_is_check(move); + bool moveIsCheck = pos.move_is_check(move, sp->dcCandidates); bool moveIsCapture = pos.move_is_capture(move); lock_grab(&(sp->lock)); @@ -1609,8 +1586,8 @@ namespace { continue; // Make and search the move. - UndoInfo u; - pos.do_move(move, u, sp->dcCandidates); + StateInfo st; + pos.do_move(move, st, sp->dcCandidates); // Try to reduce non-pv search depth by one ply if move seems not problematic, // if the move fails high will be re-searched at full depth. @@ -1632,7 +1609,7 @@ namespace { ss[sp->ply].reduction = Depth(0); value = -search(pos, ss, -(sp->beta - 1), newDepth, sp->ply+1, true, threadID); } - pos.undo_move(move, u); + pos.undo_move(move); assert(value > -VALUE_INFINITE && value < VALUE_INFINITE); @@ -1695,9 +1672,7 @@ namespace { && !thread_should_stop(threadID) && (move = sp->mp->get_next_move(sp->lock)) != MOVE_NONE) { - assert(pos.discovered_check_candidates(pos.side_to_move()) == sp->dcCandidates); - - bool moveIsCheck = pos.move_is_check(move); + bool moveIsCheck = pos.move_is_check(move, sp->dcCandidates); bool moveIsCapture = pos.move_is_capture(move); assert(move_is_ok(move)); @@ -1720,8 +1695,8 @@ namespace { Depth newDepth = sp->depth - OnePly + ext; // Make and search the move. - UndoInfo u; - pos.do_move(move, u, sp->dcCandidates); + StateInfo st; + pos.do_move(move, st, sp->dcCandidates); // Try to reduce non-pv search depth by one ply if move seems not problematic, // if the move fails high will be re-searched at full depth. @@ -1757,7 +1732,7 @@ namespace { Threads[threadID].failHighPly1 = false; } } - pos.undo_move(move, u); + pos.undo_move(move); assert(value > -VALUE_INFINITE && value < VALUE_INFINITE); @@ -1882,15 +1857,15 @@ namespace { if (includeMove) { // Find a quick score for the move - UndoInfo u; + StateInfo st; SearchStack ss[PLY_MAX_PLUS_2]; moves[count].move = mlist[i].move; moves[count].nodes = 0ULL; - pos.do_move(moves[count].move, u); + pos.do_move(moves[count].move, st); moves[count].score = -qsearch(pos, ss, -VALUE_INFINITE, VALUE_INFINITE, Depth(0), 1, 0); - pos.undo_move(moves[count].move, u); + pos.undo_move(moves[count].move); moves[count].pv[0] = moves[i].move; moves[count].pv[1] = MOVE_NONE; // FIXME count++; @@ -1992,34 +1967,6 @@ namespace { } - // init_search_stack() initializes a search stack at the beginning of a - // new search from the root. - void init_search_stack(SearchStack& ss) { - - ss.pv[0] = MOVE_NONE; - ss.pv[1] = MOVE_NONE; - ss.currentMove = MOVE_NONE; - ss.threatMove = MOVE_NONE; - ss.reduction = Depth(0); - for (int j = 0; j < KILLER_MAX; j++) - ss.killers[j] = MOVE_NONE; - } - - void init_search_stack(SearchStack ss[]) { - - for (int i = 0; i < 3; i++) - { - ss[i].pv[i] = MOVE_NONE; - ss[i].pv[i+1] = MOVE_NONE; - ss[i].currentMove = MOVE_NONE; - ss[i].threatMove = MOVE_NONE; - ss[i].reduction = Depth(0); - for (int j = 0; j < KILLER_MAX; j++) - ss[i].killers[j] = MOVE_NONE; - } - } - - // init_node() is called at the beginning of all the search functions // (search(), search_pv(), qsearch(), and so on) and initializes the search // stack object corresponding to the current node. Once every @@ -2039,13 +1986,9 @@ namespace { NodesSincePoll = 0; } } - ss[ply].pv[ply] = ss[ply].pv[ply+1] = ss[ply].currentMove = MOVE_NONE; - ss[ply+2].mateKiller = MOVE_NONE; - ss[ply].threatMove = MOVE_NONE; - ss[ply].reduction = Depth(0); - ss[ply].currentMoveCaptureValue = Value(0); - for (int j = 0; j < KILLER_MAX; j++) - ss[ply+2].killers[j] = MOVE_NONE; + + ss[ply].init(ply); + ss[ply+2].initKillers(); if(Threads[threadID].printCurrentLine) print_current_line(ss, ply, threadID); @@ -2677,9 +2620,9 @@ namespace { // splitPoint->cpus becomes 0), split() returns true. bool split(const Position &p, SearchStack *sstck, int ply, - Value *alpha, Value *beta, Value *bestValue, - Depth depth, int *moves, + Value *alpha, Value *beta, Value *bestValue, Depth depth, int *moves, MovePicker *mp, Bitboard dcCandidates, int master, bool pvNode) { + assert(p.is_ok()); assert(sstck != NULL); assert(ply >= 0 && ply < PLY_MAX);