HCha/Stockfish
1
0
Fork 0
mirror of https://github.com/HChaZZY/Stockfish.git synced 2025-12-22 01:56:58 +08:00
Code Issues Packages Projects Releases Wiki Activity

Pack 3 TT entries in 32 bytes cluster

Browse Source 
Idea from Ron Britvich

Code reworked by Marco Costalba and Joona Kiiski

Bench: 8095369

Resolves #3
Resolves #10
This commit is contained in:
Ron Britvich
2014-06-28 14:05:58 -04:00
committed by Gary Linscott
parent 7ff865b924
commit ccd823a4ff
3 changed files with 59 additions and 47 deletions
Download Patch File Download Diff File Expand all files Collapse all files

65
src/tt.h
View File

@@ -23,58 +23,69 @@
#include "misc.h"
#include "types.h"
/// The TTEntry is the 14 bytes transposition table entry, defined as below:
/// The TTEntry is the 10 bytes transposition table entry, defined as below:
///
/// key 32 bit
/// key 16 bit
/// move 16 bit
/// bound type 8 bit
/// generation 8 bit
/// value 16 bit
/// depth 16 bit
/// eval value 16 bit
/// generation 6 bit
/// bound type 2 bit
/// depth 8 bit
struct TTEntry {
Move move() const { return (Move )move16; }
Bound bound() const { return (Bound)bound8; }
Value value() const { return (Value)value16; }
Depth depth() const { return (Depth)depth16; }
Value eval_value() const { return (Value)evalValue; }
Depth depth() const { return (Depth)(depth8) + DEPTH_NONE; }
Bound bound() const { return (Bound)(genBound8 & 0x3); }
private:
friend class TranspositionTable;
void save(uint32_t k, Value v, Bound b, Depth d, Move m, uint8_t g, Value ev) {
void save(uint16_t k, Value v, Bound b, Depth d, Move m, uint8_t g, Value ev) {
key32 = (uint32_t)k;
move16 = (uint16_t)m;
bound8 = (uint8_t)b;
generation8 = (uint8_t)g;
value16 = (int16_t)v;
depth16 = (int16_t)d;
evalValue = (int16_t)ev;
key16 = (uint16_t)k;
move16 = (uint16_t)m;
value16 = (int16_t)v;
evalValue = (int16_t)ev;
depth8 = (uint8_t)(d - DEPTH_NONE);
genBound8 = g | (uint8_t)b;
}
uint32_t key32;
uint16_t key16;
uint16_t move16;
uint8_t bound8, generation8;
int16_t value16, depth16, evalValue;
int16_t value16;
int16_t evalValue;
uint8_t genBound8;
uint8_t depth8;
};
/// TTCluster is a 32 bytes cluster of TT entries consisting of:
///
/// 3 x TTEntry (3 x 10 bytes)
/// padding (2 bytes)
const unsigned TTClusterSize = 3;
struct TTCluster {
TTEntry entry[TTClusterSize];
char padding[2];
};
/// A TranspositionTable consists of a power of 2 number of clusters and each
/// cluster consists of ClusterSize number of TTEntry. Each non-empty entry
/// 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 {
static const unsigned ClusterSize = 4;
public:
~TranspositionTable() { free(mem); }
void new_search() { ++generation; }
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;
@@ -83,10 +94,10 @@ public:
void store(const Key key, Value v, Bound type, Depth d, Move m, Value statV);
private:
uint32_t hashMask;
TTEntry* table;
uint32_t clusterCount;
TTCluster* table;
void* mem;
uint8_t generation; // Size must be not bigger than TTEntry::generation8
uint8_t generation; // Size must be not bigger than TTEntry::genBound8
};
extern TranspositionTable TT;
@@ -94,11 +105,11 @@ 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.
/// get the index of the cluster inside the table.
inline TTEntry* TranspositionTable::first_entry(const Key key) const {
return table + ((uint32_t)key & hashMask);
return &table[(uint32_t)key & (clusterCount - 1)].entry[0];
}
#endif // #ifndef TT_H_INCLUDED