assert(msb((mbSize << 20) / sizeof(TTEntry)) < 32);

uint32_t size = ClusterSize << msb((mbSize << 20) / sizeof(TTEntry[ClusterSize]));

if (hashMask == size - ClusterSize)

return;

hashMask = size - ClusterSize;

free(mem);

mem = calloc(size * sizeof(TTEntry) + CACHE_LINE_SIZE - 1, 1);

if (!mem)

{

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

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

exit(EXIT_FAILURE);

}

table = (TTEntry*)((uintptr_t(mem) + CACHE_LINE_SIZE - 1) & ~(CACHE_LINE_SIZE - 1));

int c1, c2, c3;

TTEntry *tte, *replace;

uint32_t key32 = key >> 32; // Use the high 32 bits as key inside the cluster

tte = replace = first_entry(key);

for (unsigned i = 0; i < ClusterSize; ++i, ++tte)

{

if (!tte->key() || tte->key() == key32) // Empty or overwrite old

{

if (!m)

m = tte->move(); // Preserve any existing ttMove

replace = tte;

break;

}

// Implement replace strategy

c1 = (replace->generation() == generation ? 2 : 0);

c2 = (tte->generation() == generation || tte->bound() == BOUND_EXACT ? -2 : 0);

c3 = (tte->depth() < replace->depth() ? 1 : 0);

if (c1 + c2 + c3 > 0)

replace = tte;

}

replace->save(key32, v, b, d, m, generation, statV);