kate/BadFish
1
0
Fork 0
mirror of https://github.com/sockspls/badfish synced 2025-04-30 16:53:09 +00:00
Code Issues 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
Show stats Download patch file Download diff file Expand all files Collapse all files

39
src/tt.cpp
View file

@ -28,20 +28,21 @@ TranspositionTable TT; // Our global transposition table
/// TranspositionTable::resize() sets the size of the transposition table,
/// measured in megabytes. Transposition table consists of a power of 2 number
/// of clusters and each cluster consists of ClusterSize number of TTEntry.
/// of clusters and each cluster consists of TTClusterSize number of TTEntry.
void TranspositionTable::resize(uint64_t mbSize) {
assert(msb((mbSize << 20) / sizeof(TTEntry)) < 32);
assert(msb((mbSize * 1024 * 1024) / sizeof(TTCluster)) < 32);
uint32_t size = ClusterSize << msb((mbSize << 20) / sizeof(TTEntry[ClusterSize]));
uint32_t newClusterCount = 1 << msb((mbSize * 1024 * 1024) / sizeof(TTCluster));
if (hashMask == size - ClusterSize)
if (newClusterCount == clusterCount)
return;
hashMask = size - ClusterSize;
clusterCount = newClusterCount;
free(mem);
mem = calloc(size * sizeof(TTEntry) + CACHE_LINE_SIZE - 1, 1);
mem = calloc(clusterCount * sizeof(TTCluster) + CACHE_LINE_SIZE - 1, 1);
if (!mem)
{
@ -50,7 +51,7 @@ void TranspositionTable::resize(uint64_t mbSize) {
exit(EXIT_FAILURE);
}
table = (TTEntry*)((uintptr_t(mem) + CACHE_LINE_SIZE - 1) & ~(CACHE_LINE_SIZE - 1));
table = (TTCluster*)((uintptr_t(mem) + CACHE_LINE_SIZE - 1) & ~(CACHE_LINE_SIZE - 1));
}
@ -60,7 +61,7 @@ void TranspositionTable::resize(uint64_t mbSize) {
void TranspositionTable::clear() {
std::memset(table, 0, (hashMask + ClusterSize) * sizeof(TTEntry));
std::memset(table, 0, clusterCount * sizeof(TTCluster));
}
@ -71,12 +72,12 @@ void TranspositionTable::clear() {
const TTEntry* TranspositionTable::probe(const Key key) const {
TTEntry* tte = first_entry(key);
uint32_t key32 = key >> 32;
uint16_t key16 = key >> 48;
for (unsigned i = 0; i < ClusterSize; ++i, ++tte)
if (tte->key32 == key32)
for (unsigned i = 0; i < TTClusterSize; ++i, ++tte)
if (tte->key16 == key16)
{
tte->generation8 = generation; // Refresh
tte->genBound8 = generation | tte->bound(); // Refresh
return tte;
}
@ -95,13 +96,13 @@ const TTEntry* TranspositionTable::probe(const Key key) const {
void TranspositionTable::store(const Key key, Value v, Bound b, Depth d, Move m, Value statV) {
TTEntry *tte, *replace;
uint32_t key32 = key >> 32; // Use the high 32 bits as key inside the cluster
uint16_t key16 = key >> 48; // Use the high 16 bits as key inside the cluster
tte = replace = first_entry(key);
for (unsigned i = 0; i < ClusterSize; ++i, ++tte)
for (unsigned i = 0; i < TTClusterSize; ++i, ++tte)
{
if (!tte->key32 || tte->key32 == key32) // Empty or overwrite old
if (!tte->key16 || tte->key16 == key16) // Empty or overwrite old
{
if (!m)
m = tte->move(); // Preserve any existing ttMove
@ -111,11 +112,11 @@ void TranspositionTable::store(const Key key, Value v, Bound b, Depth d, Move m,
}
// Implement replace strategy
if ( ( tte->generation8 == generation || tte->bound() == BOUND_EXACT)
- (replace->generation8 == generation)
- (tte->depth16 < replace->depth16) < 0)
if ( (( tte->genBound8 & 0xFC) == generation || tte->bound() == BOUND_EXACT)
- ((replace->genBound8 & 0xFC) == generation)
- (tte->depth8 < replace->depth8) < 0)
replace = tte;
}
replace->save(key32, v, b, d, m, generation, statV);
replace->save(key16, v, b, d, m, generation, statV);
}

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

2
src/types.h
View file

@ -218,7 +218,7 @@ enum Depth {
DEPTH_QS_NO_CHECKS = -1 * ONE_PLY,
DEPTH_QS_RECAPTURES = -5 * ONE_PLY,
DEPTH_NONE = -127 * ONE_PLY
DEPTH_NONE = -6 * ONE_PLY
};
enum Square {