/// 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) {
+void TranspositionTable::resize(size_t mbSize) {
- assert(msb((mbSize << 20) / sizeof(TTEntry)) < 32);
+ size_t newClusterCount = size_t(1) << msb((mbSize * 1024 * 1024) / sizeof(TTCluster));
- uint32_t size = ClusterSize << msb((mbSize << 20) / sizeof(TTEntry[ClusterSize]));
-
- 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)
{
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));
}
void TranspositionTable::clear() {
- std::memset(table, 0, (hashMask + ClusterSize) * sizeof(TTEntry));
+ std::memset(table, 0, clusterCount * sizeof(TTCluster));
}
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;
}
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
}
// Implement replace strategy
- if ( ( tte->generation8 == generation || tte->bound() == BOUND_EXACT)
- - (replace->generation8 == generation)
- < (tte->depth16 < replace->depth16))
+ 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);
}