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
5 Copyright (C) 2015-2016 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
7 Stockfish is free software: you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation, either version 3 of the License, or
10 (at your option) any later version.
12 Stockfish is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>.
21 #ifndef SEARCH_H_INCLUDED
22 #define SEARCH_H_INCLUDED
25 #include <memory> // For std::unique_ptr
35 /// Stack struct keeps track of the information we need to remember from nodes
36 /// shallower and deeper in the tree during the search. Each search thread has
37 /// its own array of Stack objects, indexed by the current ply.
46 bool skipEarlyPruning;
50 /// RootMove struct is used for moves at the root of the tree. For each root move
51 /// we store a score and a PV (really a refutation in the case of moves which
52 /// fail low). Score is normally set at -VALUE_INFINITE for all non-pv moves.
56 explicit RootMove(Move m) : pv(1, m) {}
58 bool operator<(const RootMove& m) const { return m.score < score; } // Descending sort
59 bool operator==(const Move& m) const { return pv[0] == m; }
60 void insert_pv_in_tt(Position& pos);
61 bool extract_ponder_from_tt(Position& pos);
63 Value score = -VALUE_INFINITE;
64 Value previousScore = -VALUE_INFINITE;
68 typedef std::vector<RootMove> RootMoveVector;
70 /// LimitsType struct stores information sent by GUI about available time to
71 /// search the current move, maximum depth/time, if we are in analysis mode or
72 /// if we have to ponder while it's our opponent's turn to move.
76 LimitsType() { // Init explicitly due to broken value-initialization of non POD in MSVC
77 nodes = time[WHITE] = time[BLACK] = inc[WHITE] = inc[BLACK] = npmsec = movestogo =
78 depth = movetime = mate = infinite = ponder = 0;
81 bool use_time_management() const {
82 return !(mate | movetime | depth | nodes | infinite);
85 std::vector<Move> searchmoves;
86 int time[COLOR_NB], inc[COLOR_NB], npmsec, movestogo, depth, movetime, mate, infinite, ponder;
91 /// The SignalsType struct stores atomic flags updated during the search
92 /// typically in an async fashion e.g. to stop the search by the GUI.
95 std::atomic_bool stop, stopOnPonderhit;
98 typedef std::unique_ptr<std::stack<StateInfo>> StateStackPtr;
100 extern SignalsType Signals;
101 extern LimitsType Limits;
102 extern StateStackPtr SetupStates;
106 template<bool Root = true> uint64_t perft(Position& pos, Depth depth);
108 } // namespace Search
110 #endif // #ifndef SEARCH_H_INCLUDED