X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=be324c16edff44b08a7450edbd8d016cf65fe351;hp=2fe6a5c1f68322cf8a28790c64bda74831ca965e;hb=c8773c720af6fd5c3a8f84550ee36e5eb89f929e;hpb=0da1d6a84612c8443b3e3c9b3f74890635ce23e2 diff --git a/src/search.cpp b/src/search.cpp index 2fe6a5c1..be324c16 100644 --- a/src/search.cpp +++ b/src/search.cpp @@ -152,6 +152,16 @@ namespace { // evaluation of the position is more than NullMoveMargin below beta. const Value NullMoveMargin = Value(0x300); + //Null move search refutes move when Nullvalue >= Beta - Delta. Index is depth + //in full plies. Last index is 9+. + const Value NullMoveDeltaMidgame[] = + { Value(-8), Value( 6), Value(-15), Value( 9), Value(21), + Value(34), Value(54), Value( 59), Value(61), Value(61) }; + + const Value NullMoveDeltaEndgame[] = + { Value( 6), Value( 0), Value(-13), Value(-9), Value(-35), + Value(12), Value(24), Value( 9), Value( 5), Value( 5) }; + // Pruning criterions. See the code and comments in ok_to_prune() to // understand their precise meaning. const bool PruneEscapeMoves = false; @@ -259,15 +269,13 @@ 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); bool connected_moves(const Position &pos, Move m1, Move m2); bool value_is_mate(Value value); bool move_is_killer(Move m, const SearchStack& ss); - Depth extension(const Position &pos, Move m, bool pvNode, bool check, bool singleReply, bool mateThreat, bool* dangerous); + Depth extension(const Position &pos, Move m, bool pvNode, bool capture, bool check, bool singleReply, bool mateThreat, bool* dangerous); bool ok_to_do_nullmove(const Position &pos); bool ok_to_prune(const Position &pos, Move m, Move threat, Depth d); bool ok_to_use_TT(const TTEntry* tte, Depth depth, Value beta, int ply); @@ -290,9 +298,8 @@ 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 +332,24 @@ 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 //// @@ -589,7 +614,8 @@ void init_threads() { } // Init also the empty search stack - init_search_stack(EmptySearchStack); + EmptySearchStack.init(0); + EmptySearchStack.initKillers(); } @@ -641,8 +667,11 @@ 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; @@ -754,12 +783,12 @@ 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 +812,7 @@ namespace { { int64_t nodes; Move move; - UndoInfo u; + StateInfo st; Depth ext, newDepth; RootMoveNumber = i + 1; @@ -805,11 +834,11 @@ namespace { // Decide search depth for this move bool dangerous; - ext = extension(pos, move, true, pos.move_is_check(move), false, false, &dangerous); + ext = extension(pos, move, true, pos.move_is_capture(move), pos.move_is_check(move), false, false, &dangerous); 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 +866,7 @@ 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 +1013,9 @@ 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. @@ -1009,12 +1039,12 @@ namespace { // Decide the new search depth bool dangerous; - Depth ext = extension(pos, move, true, moveIsCheck, singleReply, mateThreat, &dangerous); + Depth ext = extension(pos, move, true, moveIsCapture, moveIsCheck, singleReply, mateThreat, &dangerous); 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 +1086,7 @@ namespace { } } } - pos.undo_move(move, u); + pos.undo_move(move); assert(value > -VALUE_INFINITE && value < VALUE_INFINITE); @@ -1182,13 +1212,19 @@ namespace { && ok_to_do_nullmove(pos) && approximateEval >= beta - NullMoveMargin) { + //Calculate correct delta. Idea and tuning from Joona Kiiski. + ScaleFactor factor[2] = { SCALE_FACTOR_NORMAL, SCALE_FACTOR_NORMAL }; + Phase phase = pos.game_phase(); + int i = Min(depth / OnePly, 9); + Value delta = scale_by_game_phase(NullMoveDeltaMidgame[i], NullMoveDeltaEndgame[i], phase, factor); + 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); + Value nullValue = -search(pos, ss, -(beta-delta-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 @@ -1203,13 +1239,13 @@ namespace { && pos.see(ss[ply + 1].currentMove) + nullValue >= beta) nullDrivenIID = true; - pos.undo_null_move(u); + pos.undo_null_move(); if (value_is_mate(nullValue)) { /* Do not return unproven mates */ } - else if (nullValue >= beta) + else if (nullValue >= beta - delta) { if (depth < 6 * OnePly) return beta; @@ -1241,7 +1277,7 @@ namespace { else if ( !value_is_mate(beta) && approximateEval < beta - RazorMargin && depth < RazorDepth - && (RazorAtDepthOne || depth >= 2*OnePly) + && (RazorAtDepthOne || depth > OnePly) && ttMove == MOVE_NONE && !pos.has_pawn_on_7th(pos.side_to_move())) { @@ -1305,7 +1341,7 @@ namespace { // Decide the new search depth bool dangerous; - Depth ext = extension(pos, move, false, moveIsCheck, singleReply, mateThreat, &dangerous); + Depth ext = extension(pos, move, false, moveIsCapture, moveIsCheck, singleReply, mateThreat, &dangerous); Depth newDepth = depth - OnePly + ext; // Futility pruning @@ -1337,8 +1373,8 @@ 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 +1397,7 @@ 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 +1507,8 @@ 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. @@ -1516,10 +1553,10 @@ 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); @@ -1595,7 +1632,7 @@ namespace { // Decide the new search depth. bool dangerous; - Depth ext = extension(pos, move, false, moveIsCheck, false, false, &dangerous); + Depth ext = extension(pos, move, false, moveIsCapture, moveIsCheck, false, false, &dangerous); Depth newDepth = sp->depth - OnePly + ext; // Prune? @@ -1608,8 +1645,8 @@ 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. @@ -1631,7 +1668,7 @@ 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); @@ -1713,12 +1750,12 @@ namespace { // Decide the new search depth. bool dangerous; - Depth ext = extension(pos, move, true, moveIsCheck, false, false, &dangerous); + Depth ext = extension(pos, move, true, moveIsCapture, moveIsCheck, false, false, &dangerous); 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. @@ -1754,7 +1791,7 @@ namespace { Threads[threadID].failHighPly1 = false; } } - pos.undo_move(move, u); + pos.undo_move(move); assert(value > -VALUE_INFINITE && value < VALUE_INFINITE); @@ -1879,15 +1916,15 @@ 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++; @@ -1989,34 +2026,6 @@ 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 @@ -2036,13 +2045,9 @@ 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); @@ -2113,7 +2118,7 @@ namespace { // Case 4: The destination square for m2 is attacked by the moving piece // in m1: - if(pos.piece_attacks_square(t1, t2)) + if(pos.piece_attacks_square(pos.piece_on(t1), t1, t2)) return true; // Case 5: Discovered check, checking piece is the piece moved in m1: @@ -2178,7 +2183,7 @@ namespace { // extended, as example because the corresponding UCI option is set to zero, // the move is marked as 'dangerous' so, at least, we avoid to prune it. - Depth extension(const Position &pos, Move m, bool pvNode, bool check, + Depth extension(const Position& pos, Move m, bool pvNode, bool capture, bool check, bool singleReply, bool mateThreat, bool* dangerous) { assert(m != MOVE_NONE); @@ -2195,18 +2200,21 @@ namespace { if (mateThreat) result += MateThreatExtension[pvNode]; - if (pos.move_is_pawn_push_to_7th(m)) + if (pos.type_of_piece_on(move_from(m)) == PAWN) { - result += PawnPushTo7thExtension[pvNode]; - *dangerous = true; - } - if (pos.move_is_passed_pawn_push(m)) - { - result += PassedPawnExtension[pvNode]; - *dangerous = true; + if (pos.move_is_pawn_push_to_7th(m)) + { + result += PawnPushTo7thExtension[pvNode]; + *dangerous = true; + } + if (pos.move_is_passed_pawn_push(m)) + { + result += PassedPawnExtension[pvNode]; + *dangerous = true; + } } - if ( pos.move_is_capture(m) + if ( capture && pos.type_of_piece_on(move_to(m)) != PAWN && ( pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) - pos.midgame_value_of_piece_on(move_to(m)) == Value(0)) @@ -2218,7 +2226,7 @@ namespace { } if ( pvNode - && pos.move_is_capture(m) + && capture && pos.type_of_piece_on(move_to(m)) != PAWN && pos.see(m) >= 0) { @@ -2671,9 +2679,9 @@ 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);