bit_read_4BITS (Bit_Chain *dat)
{
  // clang-format off
  BITCODE_4BITS b =
         bit_read_B (dat) << 3 |
         bit_read_B (dat) << 2 |
         bit_read_B (dat) << 1 |
         bit_read_B (dat);
  // clang-format on
  return b;
}
bit_read_4BITS (Bit_Chain *dat)
{
   
  BITCODE_4BITS b =
         bit_read_B (dat) << 3 |
         bit_read_B (dat) << 2 |
         bit_read_B (dat) << 1 |
         bit_read_B (dat);
   
  return b;
}