2 Stockfish, a UCI chess playing engine derived from Glaurung 2.1
3 Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
4 Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
6 Stockfish is free software: you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation, either version 3 of the License, or
9 (at your option) any later version.
11 Stockfish is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
20 #ifndef SEARCH_H_INCLUDED
21 #define SEARCH_H_INCLUDED
24 #include <memory> // For std::unique_ptr
36 /// Stack struct keeps track of the information we need to remember from nodes
37 /// shallower and deeper in the tree during the search. Each search thread has
38 /// its own array of Stack objects, indexed by the current ply.
41 SplitPoint* splitPoint;
50 bool skipEarlyPruning;
54 /// RootMove struct is used for moves at the root of the tree. For each root move
55 /// we store a score and a PV (really a refutation in the case of moves which
56 /// fail low). Score is normally set at -VALUE_INFINITE for all non-pv moves.
60 explicit RootMove(Move m) : pv(1, m) {}
62 bool operator<(const RootMove& m) const { return score > m.score; } // Ascending sort
63 bool operator==(const Move& m) const { return pv[0] == m; }
64 void insert_pv_in_tt(Position& pos);
65 bool extract_ponder_from_tt(Position& pos);
67 Value score = -VALUE_INFINITE;
68 Value previousScore = -VALUE_INFINITE;
72 typedef std::vector<RootMove> RootMoveVector;
74 /// LimitsType struct stores information sent by GUI about available time to
75 /// search the current move, maximum depth/time, if we are in analysis mode or
76 /// if we have to ponder while it's our opponent's turn to move.
80 LimitsType() { // Init explicitly due to broken value-initialization of non POD in MSVC
81 nodes = time[WHITE] = time[BLACK] = inc[WHITE] = inc[BLACK] = npmsec = movestogo =
82 depth = movetime = mate = infinite = ponder = 0;
85 bool use_time_management() const {
86 return !(mate | movetime | depth | nodes | infinite);
89 std::vector<Move> searchmoves;
90 int time[COLOR_NB], inc[COLOR_NB], npmsec, movestogo, depth, movetime, mate, infinite, ponder;
95 /// The SignalsType struct stores atomic flags updated during the search
96 /// typically in an async fashion e.g. to stop the search by the GUI.
99 std::atomic<bool> stop, stopOnPonderhit, firstRootMove, failedLowAtRoot;
102 typedef std::unique_ptr<std::stack<StateInfo>> StateStackPtr;
104 extern SignalsType Signals;
105 extern LimitsType Limits;
106 extern StateStackPtr SetupStates;
110 template<bool Root> uint64_t perft(Position& pos, Depth depth);
112 } // namespace Search
114 #endif // #ifndef SEARCH_H_INCLUDED