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
34 /// Stack struct keeps track of the information we need to remember from nodes
35 /// shallower and deeper in the tree during the search. Each search thread has
36 /// its own array of Stack objects, indexed by the current ply.
45 bool skipEarlyPruning;
49 /// RootMove struct is used for moves at the root of the tree. For each root move
50 /// we store a score and a PV (really a refutation in the case of moves which
51 /// fail low). Score is normally set at -VALUE_INFINITE for all non-pv moves.
55 explicit RootMove(Move m) : pv(1, m) {}
57 bool operator<(const RootMove& m) const { return m.score < score; } // Descending sort
58 bool operator==(const Move& m) const { return pv[0] == m; }
59 void insert_pv_in_tt(Position& pos);
60 bool extract_ponder_from_tt(Position& pos);
62 Value score = -VALUE_INFINITE;
63 Value previousScore = -VALUE_INFINITE;
67 typedef std::vector<RootMove> RootMoveVector;
69 /// LimitsType struct stores information sent by GUI about available time to
70 /// search the current move, maximum depth/time, if we are in analysis mode or
71 /// if we have to ponder while it's our opponent's turn to move.
75 LimitsType() { // Init explicitly due to broken value-initialization of non POD in MSVC
76 nodes = time[WHITE] = time[BLACK] = inc[WHITE] = inc[BLACK] = npmsec = movestogo =
77 depth = movetime = mate = infinite = ponder = 0;
80 bool use_time_management() const {
81 return !(mate | movetime | depth | nodes | infinite);
84 std::vector<Move> searchmoves;
85 int time[COLOR_NB], inc[COLOR_NB], npmsec, movestogo, depth, movetime, mate, infinite, ponder;
90 /// The SignalsType struct stores atomic flags updated during the search
91 /// typically in an async fashion e.g. to stop the search by the GUI.
94 std::atomic_bool stop, stopOnPonderhit;
97 typedef std::unique_ptr<std::stack<StateInfo>> StateStackPtr;
99 extern SignalsType Signals;
100 extern LimitsType Limits;
101 extern StateStackPtr SetupStates;
105 template<bool Root = true> uint64_t perft(Position& pos, Depth depth);
107 } // namespace Search
109 #endif // #ifndef SEARCH_H_INCLUDED