_bit_offset
return (1UL << _bit_offset(_bit));
return ((_BITSTR_MASK << _bit_offset(_start)) &
(_BITSTR_MASK >> (_BITSTR_BITS - _bit_offset(_stop) - 1)));
if (_bit_offset(_start) != 0)
if (_bit_offset(_start) != 0)
mask = _bit_make_mask(_start, _bit_offset(curbitstr_len - 1));
mask = _bit_make_mask(0, _bit_offset(_nbits - 1));