private void ExpandBlock(ulong blockNumber)
{
for (var i = 0; i < 16; i++)
{
_w[i] = Bytes_To_UInt32(_m, blockNumber * 64 + (ulong)i * 4);
}
for (var i = 16; i <= 63; i++)
{
_w[i] = _w[i - 16] + S0.Compile()(_w[i - 15]) + _w[i - 7] + S1.Compile()(_w[i - 2]);
}
}