assert(d / ONE_PLY * ONE_PLY == d);

// Preserve any existing move for the same position

if (m || (k >> 48) != key16)

move16 = (uint16_t)m;

// Overwrite less valuable entries

if ( (k >> 48) != key16

|| d / ONE_PLY > depth8 - 4

|| b == BOUND_EXACT)

{

key16 = (uint16_t)(k >> 48);

value16 = (int16_t)v;

eval16 = (int16_t)ev;

genBound8 = (uint8_t)(TT.generation8 | b);

depth8 = (int8_t)(d / ONE_PLY);

}

clusterCount = mbSize * 1024 * 1024 / sizeof(Cluster);

free(mem);

mem = malloc(clusterCount * sizeof(Cluster) + CacheLineSize - 1);

if (!mem)

{

std::cerr << "Failed to allocate " << mbSize

<< "MB for transposition table." << std::endl;

exit(EXIT_FAILURE);

}

table = (Cluster*)((uintptr_t(mem) + CacheLineSize - 1) & ~(CacheLineSize - 1));

clear();

std::vector<std::thread> threads;

for (size_t idx = 0; idx < Options["Threads"]; idx++)

{

threads.push_back(std::thread([this, idx]() {

// Thread binding gives faster search on systems with a first-touch policy

if (Options["Threads"] >= 8)

WinProcGroup::bindThisThread(idx);

// Each thread will zero its part of the hash table

const size_t stride = clusterCount / Options["Threads"],

start = stride * idx,

len = idx != Options["Threads"] - 1 ?

stride : clusterCount - start;

std::memset(&table[start], 0, len * sizeof(Cluster));

}));

}

for (std::thread& th: threads)

th.join();

int cnt = 0;

for (int i = 0; i < 1000 / ClusterSize; i++)

{

const TTEntry* tte = &table[i].entry[0];

for (int j = 0; j < ClusterSize; j++)

if ((tte[j].genBound8 & 0xFC) == generation8)

cnt++;

}

return cnt;