2 Stockfish, a UCI chess playing engine derived from Glaurung 2.1
3 Copyright (C) 2004-2020 The Stockfish developers (see AUTHORS file)
5 Stockfish is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation, either version 3 of the License, or
8 (at your option) any later version.
10 Stockfish is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>.
19 #ifndef SEARCH_H_INCLUDED
20 #define SEARCH_H_INCLUDED
32 /// Threshold used for countermoves based pruning
33 constexpr int CounterMovePruneThreshold = 0;
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.
42 PieceToHistory* continuationHistory;
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) {}
61 bool extract_ponder_from_tt(Position& pos);
62 bool operator==(const Move& m) const { return pv[0] == m; }
63 bool operator<(const RootMove& m) const { // Sort in descending order
64 return m.score != score ? m.score < score
65 : m.previousScore < previousScore;
68 Value score = -VALUE_INFINITE;
69 Value previousScore = -VALUE_INFINITE;
72 int bestMoveCount = 0;
77 typedef std::vector<RootMove> RootMoves;
80 /// LimitsType struct stores information sent by GUI about available time to
81 /// search the current move, maximum depth/time, or if we are in analysis mode.
85 LimitsType() { // Init explicitly due to broken value-initialization of non POD in MSVC
86 time[WHITE] = time[BLACK] = inc[WHITE] = inc[BLACK] = npmsec = movetime = TimePoint(0);
87 movestogo = depth = mate = perft = infinite = 0;
91 bool use_time_management() const {
92 return time[WHITE] || time[BLACK];
95 std::vector<Move> searchmoves;
96 TimePoint time[COLOR_NB], inc[COLOR_NB], npmsec, movetime, startTime;
97 int movestogo, depth, mate, perft, infinite;
101 extern LimitsType Limits;
106 } // namespace Search
108 #endif // #ifndef SEARCH_H_INCLUDED