X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Ftt.h;h=534409f32800bfc34110d931cac3bd29e0827cfe;hp=b43489dd796ebc8aff60902f12766b5ed5bedc7f;hb=15e21911110f9d459c4fef2bb17903d97345d0b9;hpb=62c68c2d2174ee5158cf3282c7429b15483f3d51 diff --git a/src/tt.h b/src/tt.h index b43489dd..534409f3 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) 2008-2010 Marco Costalba, Joona Kiiski, Tord Romstad + Copyright (C) 2008-2014 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 @@ -17,125 +17,98 @@ along with this program. If not, see . */ - -#if !defined(TT_H_INCLUDED) +#ifndef TT_H_INCLUDED #define TT_H_INCLUDED -//// -//// Includes -//// - -#include "depth.h" -#include "position.h" -#include "value.h" - - -//// -//// Types -//// +#include "misc.h" +#include "types.h" -/// The TTEntry class is the class of transposition table entries +/// The TTEntry is the 10 bytes transposition table entry, defined as below: /// -/// A TTEntry needs 96 bits to be stored -/// -/// 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 -/// -/// bit 0-16: move -/// bit 17-19: not used -/// bit 20-22: value type -/// bit 23-31: generation +/// key 16 bit +/// move 16 bit +/// value 16 bit +/// eval value 16 bit +/// generation 6 bit +/// bound type 2 bit +/// depth 8 bit + +struct TTEntry { + + Move move() const { return (Move )move16; } + Value value() const { return (Value)value16; } + Value eval_value() const { return (Value)evalValue; } + Depth depth() const { return (Depth)depth8; } + Bound bound() const { return (Bound)(genBound8 & 0x3); } + +private: + friend class TranspositionTable; -class TTEntry { + void save(uint16_t k, Value v, Bound b, Depth d, Move m, uint8_t g, Value ev) { -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); + key16 = (uint16_t)k; + move16 = (uint16_t)m; + value16 = (int16_t)v; + evalValue = (int16_t)ev; + genBound8 = (uint8_t)(g | b); + depth8 = (int8_t)d; } - uint32_t key() const { return key32; } - Depth depth() const { return Depth(depth16); } - Move move() const { return Move(data & 0x1FFFF); } - Value value() const { return Value(value16); } - ValueType type() const { return ValueType((data >> 20) & 7); } - int generation() const { return data >> 23; } - Value static_value() const { return Value(staticValue); } - Value king_danger() const { return Value(kingDanger); } - -private: - uint32_t key32; - uint32_t data; - int16_t value16; - int16_t depth16; - int16_t staticValue; - int16_t kingDanger; + uint16_t key16; + uint16_t move16; + int16_t value16; + int16_t evalValue; + uint8_t genBound8; + int8_t depth8; }; +/// TTCluster is a 32 bytes cluster of TT entries consisting of: +/// +/// 3 x TTEntry (3 x 10 bytes) +/// padding (2 bytes) -/// 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. +const unsigned TTClusterSize = 3; struct TTCluster { - TTEntry data[ClusterSize]; + TTEntry entry[TTClusterSize]; + char padding[2]; }; - -/// 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. +/// A TranspositionTable consists of a power of 2 number of clusters and each +/// cluster consists of TTClusterSize number of TTEntry. Each non-empty entry +/// contains information of exactly one position. The size of a cluster should +/// not be bigger than a cache line size. In case it is less, it should be padded +/// to guarantee always aligned accesses. class TranspositionTable { public: - TranspositionTable(); - ~TranspositionTable(); - void set_size(size_t mbSize); + ~TranspositionTable() { free(mem); } + void new_search() { generation += 4; } // Lower 2 bits are used by Bound + + const TTEntry* probe(const Key key) const; + TTEntry* first_entry(const Key key) const; + void resize(size_t mbSize); void clear(); - 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 bestMove, Move pv[], const int PLY_MAX); - int full() const; - TTEntry* first_entry(const Key posKey) const; + void store(const Key key, Value v, Bound type, Depth d, Move m, Value statV); 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; + size_t clusterCount; + TTCluster* table; + void* mem; + uint8_t generation; // Size must be not bigger than TTEntry::genBound8 }; 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. +/// 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 inside the table. -inline TTEntry* TranspositionTable::first_entry(const Key posKey) const { +inline TTEntry* TranspositionTable::first_entry(const Key key) const { - return entries[uint32_t(posKey) & (size - 1)].data; + return &table[(size_t)key & (clusterCount - 1)].entry[0]; } -#endif // !defined(TT_H_INCLUDED) +#endif // #ifndef TT_H_INCLUDED