X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Ftt.h;h=b43489dd796ebc8aff60902f12766b5ed5bedc7f;hp=76ecad81e101254dea4832984f2022dd9e2055da;hb=62c68c2d2174ee5158cf3282c7429b15483f3d51;hpb=659c54582ddb1bbbf80f7022a80c027ab0bd4c42 diff --git a/src/tt.h b/src/tt.h index 76ecad81..b43489dd 100644 --- a/src/tt.h +++ b/src/tt.h @@ -1,7 +1,7 @@ /* Stockfish, a UCI chess playing engine derived from Glaurung 2.1 Copyright (C) 2004-2008 Tord Romstad (Glaurung author) - Copyright (C) 2008 Marco Costalba + Copyright (C) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad Stockfish is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -36,12 +36,12 @@ /// The TTEntry class is the class of transposition table entries /// -/// A TTEntry needs 128 bits to be stored +/// A TTEntry needs 96 bits to be stored /// -/// bit 0-63: key -/// bit 64-95: data -/// bit 96-111: value -/// bit 112-127: depth +/// bit 0-31: key +/// bit 32-63: data +/// bit 64-79: value +/// bit 80-95: depth /// /// the 32 bits of the data field are so defined /// @@ -53,55 +53,89 @@ class TTEntry { public: - TTEntry(); - TTEntry(Key k, Value v, ValueType t, Depth d, Move m, int generation); - Key key() const { return key_; } - Depth depth() const { return Depth(depth_); } + void save(uint32_t k, Value v, ValueType t, Depth d, Move m, int g, Value statV, Value kd) { + + key32 = k; + data = (m & 0x1FFFF) | (t << 20) | (g << 23); + value16 = int16_t(v); + depth16 = int16_t(d); + staticValue = int16_t(statV); + kingDanger = int16_t(kd); + } + + uint32_t key() const { return key32; } + Depth depth() const { return Depth(depth16); } Move move() const { return Move(data & 0x1FFFF); } - Value value() const { return Value(value_); } + Value value() const { return Value(value16); } ValueType type() const { return ValueType((data >> 20) & 7); } - int generation() const { return (data >> 23); } + int generation() const { return data >> 23; } + Value static_value() const { return Value(staticValue); } + Value king_danger() const { return Value(kingDanger); } private: - Key key_; + uint32_t key32; uint32_t data; - int16_t value_; - int16_t depth_; + int16_t value16; + int16_t depth16; + int16_t staticValue; + int16_t kingDanger; }; -/// The transposition table class. This is basically just a huge array + +/// This is the number of TTEntry slots for each position +const int ClusterSize = 4; + +/// Each group of ClusterSize number of TTEntry form a TTCluster +/// that is indexed by a single position key. TTCluster size must +/// be not bigger then a cache line size, in case it is less then +/// it should be padded to guarantee always aligned accesses. + +struct TTCluster { + TTEntry data[ClusterSize]; +}; + + +/// The transposition table class. This is basically just a huge array /// containing TTEntry objects, and a few methods for writing new entries /// and reading new ones. class TranspositionTable { public: - TranspositionTable(unsigned mbSize); + TranspositionTable(); ~TranspositionTable(); - void set_size(unsigned mbSize); + void set_size(size_t mbSize); void clear(); - void store(const Position &pos, Value v, Depth d, Move m, ValueType type); - TTEntry* retrieve(const Position &pos) const; + void store(const Key posKey, Value v, ValueType type, Depth d, Move m, Value statV, Value kingD); + TTEntry* retrieve(const Key posKey) const; void new_search(); - void insert_pv(const Position &pos, Move pv[]); - int full(); + void insert_pv(const Position& pos, Move pv[]); + void extract_pv(const Position& pos, Move bestMove, Move pv[], const int PLY_MAX); + int full() const; + TTEntry* first_entry(const Key posKey) const; private: - inline TTEntry* first_entry(const Position &pos) const; - - unsigned size; - int writes; - TTEntry* entries; + // Be sure 'writes' is at least one cache line away + // from read only variables. + unsigned char pad_before[64 - sizeof(unsigned)]; + unsigned writes; // heavy SMP read/write access here + unsigned char pad_after[64]; + + size_t size; + TTCluster* entries; uint8_t generation; }; +extern TranspositionTable TT; -//// -//// Constants and variables -//// -// Default transposition table size, in megabytes: -const int TTDefaultSize = 32; +/// TranspositionTable::first_entry returns a pointer to the first +/// entry of a cluster given a position. The low 32 bits of the key +/// are used to get the index in the table. + +inline TTEntry* TranspositionTable::first_entry(const Key posKey) const { + return entries[uint32_t(posKey) & (size - 1)].data; +} #endif // !defined(TT_H_INCLUDED)