X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Ftt.h;h=94ee78e70f233f9126bee035e1213403551bee8f;hp=bcc761acf325da0999838b2f209cb4faab92bb33;hb=06c14d0a37c370c1102494aea6a69b5fe4f5250f;hpb=47ee6d9fa4091aa05f6fedb62a2bb652b0422f08 diff --git a/src/tt.h b/src/tt.h index bcc761ac..94ee78e7 100644 --- a/src/tt.h +++ b/src/tt.h @@ -21,12 +21,10 @@ #if !defined(TT_H_INCLUDED) #define TT_H_INCLUDED -//// -//// Includes -//// +#include #include "depth.h" -#include "position.h" +#include "move.h" #include "value.h" @@ -34,61 +32,100 @@ //// 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 + ((uint32_t)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 0-15: move +/// bit 16-20: not used +/// bit 21-22: value type /// bit 23-31: generation class TTEntry { public: - 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); + void save(uint32_t k, Value v, ValueType t, Depth d, Move m, int g, Value statV, Value statM) { + + key32 = (uint32_t)k; + move16 = (uint16_t)m; + valueType = (uint8_t)t; + generation8 = (uint8_t)g; + value16 = (int16_t)v; + depth16 = (int16_t)d; + staticValue = (int16_t)statV; + staticMargin = (int16_t)statM; } + void set_generation(int g) { generation8 = (uint8_t)g; } uint32_t key() const { return key32; } Depth depth() const { return Depth(depth16); } - Move move() const { return Move(data & 0x1FFFF); } + Move move() const { return Move(move16); } Value value() const { return Value(value16); } - ValueType type() const { return ValueType((data >> 20) & 7); } - int generation() const { return data >> 23; } + ValueType type() const { return ValueType(valueType); } + int generation() const { return generation8; } Value static_value() const { return Value(staticValue); } - Value king_danger() const { return Value(kingDanger); } + Value static_value_margin() const { return Value(staticMargin); } private: uint32_t key32; - uint32_t data; + uint16_t move16; + uint8_t valueType; + uint8_t generation8; int16_t value16; int16_t depth16; int16_t staticValue; - int16_t kingDanger; + int16_t staticMargin; }; -/// 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. 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. +/// 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]; @@ -96,11 +133,14 @@ struct TTCluster { /// 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(); @@ -109,33 +149,34 @@ public: 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[]); - 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: - // 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 low 32 bits of the key -/// are used to get the index in the table. +/// 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; + 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)