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) 2015-2020 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
34 /// Threshold used for countermoves based pruning
35 constexpr int CounterMovePruneThreshold = 0;
38 /// Stack struct keeps track of the information we need to remember from nodes
39 /// shallower and deeper in the tree during the search. Each search thread has
40 /// its own array of Stack objects, indexed by the current ply.
44 PieceToHistory* continuationHistory;
56 /// RootMove struct is used for moves at the root of the tree. For each root move
57 /// we store a score and a PV (really a refutation in the case of moves which
58 /// fail low). Score is normally set at -VALUE_INFINITE for all non-pv moves.
62 explicit RootMove(Move m) : pv(1, m) {}
63 bool extract_ponder_from_tt(Position& pos);
64 bool operator==(const Move& m) const { return pv[0] == m; }
65 bool operator<(const RootMove& m) const { // Sort in descending order
66 return m.score != score ? m.score < score
67 : m.previousScore < previousScore;
70 Value score = -VALUE_INFINITE;
71 Value previousScore = -VALUE_INFINITE;
74 int bestMoveCount = 0;
79 typedef std::vector<RootMove> RootMoves;
82 /// LimitsType struct stores information sent by GUI about available time to
83 /// search the current move, maximum depth/time, or if we are in analysis mode.
87 LimitsType() { // Init explicitly due to broken value-initialization of non POD in MSVC
88 time[WHITE] = time[BLACK] = inc[WHITE] = inc[BLACK] = npmsec = movetime = TimePoint(0);
89 movestogo = depth = mate = perft = infinite = 0;
93 bool use_time_management() const {
94 return !(mate | movetime | depth | nodes | perft | infinite);
97 std::vector<Move> searchmoves;
98 TimePoint time[COLOR_NB], inc[COLOR_NB], npmsec, movetime, startTime;
99 int movestogo, depth, mate, perft, infinite;
103 extern LimitsType Limits;
108 } // namespace Search
110 #endif // #ifndef SEARCH_H_INCLUDED