X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Ftt.h;h=f2928fb9e84b4b754ae9c1ecfb9a1c01b7778a56;hp=530cc4053719f168a25e5f389a82e6160eb4f6fd;hb=0ddf84870ad9f7fb4309e992e1e5eae968577958;hpb=de0c9e84ca6e41d5cb7c9691edc5918d417c265d diff --git a/src/tt.h b/src/tt.h index 530cc405..f2928fb9 100644 --- a/src/tt.h +++ b/src/tt.h @@ -26,7 +26,7 @@ //// #include "depth.h" -#include "position.h" +#include "move.h" #include "value.h" @@ -34,91 +34,147 @@ //// Types //// + +/// A simple fixed size hash table used to store pawns and material +/// configurations. It is basically just an array of Entry objects. +/// Without cluster concept or overwrite policy. + +template +class SimpleHash { + + SimpleHash(const SimpleHash&); + SimpleHash& operator=(const SimpleHash&); + +public: + SimpleHash() { + + entries = new Entry[HashSize]; + if (!entries) + { + std::cerr << "Failed to allocate " << HashSize * sizeof(Entry) + << " bytes for material hash table." << std::endl; + exit(EXIT_FAILURE); + } + memset(entries, 0, HashSize * sizeof(Entry)); + } + + ~SimpleHash() { delete [] entries; } + + Entry* find(Key key) const { return entries + unsigned(key & (HashSize - 1)); } + +protected: + Entry* entries; +}; + + /// The TTEntry class is the class of transposition table entries /// -/// A TTEntry needs 96 bits to be stored +/// A TTEntry needs 128 bits to be stored /// /// bit 0-31: key /// bit 32-63: data /// bit 64-79: value /// bit 80-95: depth +/// bit 96-111: static value +/// bit 112-127: margin of static value /// /// the 32 bits of the data field are so defined /// /// bit 0-16: move -/// bit 17-19: not used -/// bit 20-22: value type +/// bit 17-20: not used +/// bit 21-22: value type /// bit 23-31: generation class TTEntry { public: - TTEntry() {} - TTEntry(uint32_t k, Value v, ValueType t, Depth d, Move m, int generation) - : key_ (k), data((m & 0x1FFFF) | (t << 20) | (generation << 23)), - value_(int16_t(v)), depth_(int16_t(d)) {} - - uint32_t 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 << 21) | (g << 23); + value16 = (int16_t)v; + depth16 = (int16_t)d; + staticValue = (int16_t)statV; + staticValueMargin = (int16_t)kd; + } + void set_generation(int g) { data = move() | (type() << 21) | (g << 23); } + + 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_); } - ValueType type() const { return ValueType((data >> 20) & 7); } - int generation() const { return (data >> 23); } + Value value() const { return Value(value16); } + ValueType type() const { return ValueType((data >> 21) & 3); } + int generation() const { return data >> 23; } + Value static_value() const { return Value(staticValue); } + Value static_value_margin() const { return Value(staticValueMargin); } private: - uint32_t key_; + uint32_t key32; uint32_t data; - int16_t value_; - int16_t depth_; + int16_t value16; + int16_t depth16; + int16_t staticValue; + int16_t staticValueMargin; }; -/// This is the number of TTEntry slots for each position +/// This is the number of TTEntry slots for each cluster const int ClusterSize = 4; -/// Each group of ClusterSize number of TTEntry form a TTCluster -/// that is indexed by a single position key. Cluster is padded -/// to a cache line size so to guarantee always aligned accesses. +/// TTCluster consists of ClusterSize number of TTEntries. +/// Size of TTCluster must not be bigger than a cache line size. +/// In case it is less, it should be padded to guarantee always aligned accesses. struct TTCluster { TTEntry data[ClusterSize]; - char cache_line_padding[64 - sizeof(TTEntry[ClusterSize])]; }; /// The transposition table class. This is basically just a huge array -/// containing TTEntry objects, and a few methods for writing new entries +/// containing TTCluster objects, and a few methods for writing new entries /// and reading new ones. class TranspositionTable { + TranspositionTable(const TranspositionTable&); + TranspositionTable& operator=(const TranspositionTable&); + public: TranspositionTable(); ~TranspositionTable(); void set_size(size_t mbSize); void clear(); - void store(const Key posKey, Value v, ValueType type, Depth d, Move m); + void store(const Key posKey, Value v, ValueType type, Depth d, Move m, Value statV, Value kingD); TTEntry* retrieve(const Key posKey) const; - void prefetch(const Key posKey) const; void new_search(); - void insert_pv(const Position& pos, Move pv[]); - void extract_pv(const Position& pos, Move pv[], const int PLY_MAX); - int full() const; + TTEntry* first_entry(const Key posKey) const; + void refresh(const TTEntry* tte) const; private: - inline TTEntry* first_entry(const Key posKey) const; - - // 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; + uint8_t generation; // To properly compare, size must be smaller then TT stored value }; extern TranspositionTable TT; + +/// TranspositionTable::first_entry returns a pointer to the first +/// entry of a cluster given a position. The lowest order bits of the key +/// are used to get the index of the cluster. + +inline TTEntry* TranspositionTable::first_entry(const Key posKey) const { + + return entries[((uint32_t)posKey) & (size - 1)].data; +} + + +/// TranspositionTable::refresh updates the 'generation' value of the TTEntry +/// to avoid aging. Normally called after a TT hit, before to return. + +inline void TranspositionTable::refresh(const TTEntry* tte) const { + + const_cast(tte)->set_generation(generation); +} + #endif // !defined(TT_H_INCLUDED)