/*
Stockfish, a UCI chess playing engine derived from Glaurung 2.1
- Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
- Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2004-2020 The Stockfish developers (see AUTHORS file)
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-
-#if !defined(SEARCH_H_INCLUDED)
+#ifndef SEARCH_H_INCLUDED
#define SEARCH_H_INCLUDED
-////
-//// Includes
-////
-
-#include "depth.h"
-#include "move.h"
-#include "value.h"
+#include <vector>
+#include "misc.h"
+#include "movepick.h"
+#include "types.h"
-////
-//// Constants
-////
+class Position;
-const int PLY_MAX = 100;
-const int PLY_MAX_PLUS_2 = 102;
-const int KILLER_MAX = 2;
+namespace Search {
+/// Threshold used for countermoves based pruning
+constexpr int CounterMovePruneThreshold = 0;
-////
-//// Types
-////
-/// The SearchStack struct keeps track of the information we need to remember
-/// from nodes shallower and deeper in the tree during the search. Each
-/// search thread has its own array of SearchStack objects, indexed by the
-/// current ply.
-struct EvalInfo;
+/// Stack struct keeps track of the information we need to remember from nodes
+/// shallower and deeper in the tree during the search. Each search thread has
+/// its own array of Stack objects, indexed by the current ply.
-struct SearchStack {
- Move pv[PLY_MAX_PLUS_2];
+struct Stack {
+ Move* pv;
+ PieceToHistory* continuationHistory;
+ int ply;
Move currentMove;
- Move mateKiller;
- Move threatMove;
Move excludedMove;
- Move killers[KILLER_MAX];
- Depth reduction;
- Value eval;
- bool skipNullMove;
+ Move killers[2];
+ Value staticEval;
+ int statScore;
+ int moveCount;
+ bool inCheck;
+};
+
+
+/// RootMove struct is used for moves at the root of the tree. For each root move
+/// we store a score and a PV (really a refutation in the case of moves which
+/// fail low). Score is normally set at -VALUE_INFINITE for all non-pv moves.
+
+struct RootMove {
+
+ explicit RootMove(Move m) : pv(1, m) {}
+ bool extract_ponder_from_tt(Position& pos);
+ bool operator==(const Move& m) const { return pv[0] == m; }
+ bool operator<(const RootMove& m) const { // Sort in descending order
+ return m.score != score ? m.score < score
+ : m.previousScore < previousScore;
+ }
- void init(int ply);
- void initKillers();
+ Value score = -VALUE_INFINITE;
+ Value previousScore = -VALUE_INFINITE;
+ int selDepth = 0;
+ int tbRank = 0;
+ int bestMoveCount = 0;
+ Value tbScore;
+ std::vector<Move> pv;
};
+typedef std::vector<RootMove> RootMoves;
+
+
+/// LimitsType struct stores information sent by GUI about available time to
+/// search the current move, maximum depth/time, or if we are in analysis mode.
+
+struct LimitsType {
+
+ LimitsType() { // Init explicitly due to broken value-initialization of non POD in MSVC
+ time[WHITE] = time[BLACK] = inc[WHITE] = inc[BLACK] = npmsec = movetime = TimePoint(0);
+ movestogo = depth = mate = perft = infinite = 0;
+ nodes = 0;
+ }
+
+ bool use_time_management() const {
+ return time[WHITE] || time[BLACK];
+ }
+
+ std::vector<Move> searchmoves;
+ TimePoint time[COLOR_NB], inc[COLOR_NB], npmsec, movetime, startTime;
+ int movestogo, depth, mate, perft, infinite;
+ int64_t nodes;
+};
-////
-//// Prototypes
-////
+extern LimitsType Limits;
-extern void init_search();
-extern void init_threads();
-extern void exit_threads();
-extern bool think(const Position &pos, bool infinite, bool ponder, int side_to_move,
- int time[], int increment[], int movesToGo, int maxDepth,
- int maxNodes, int maxTime, Move searchMoves[]);
-extern int perft(Position &pos, Depth depth);
-extern int64_t nodes_searched();
+void init();
+void clear();
+} // namespace Search
-#endif // !defined(SEARCH_H_INCLUDED)
+#endif // #ifndef SEARCH_H_INCLUDED