class LIR_OprDesc: public CompilationResourceObj {
 public:
  // value structure:
  // data opr-type opr-kind
  // +--------------+-------+-------+
  // [max...........|7 6 5 4|3 2 1 0]
  // ^
  // is_pointer bit
  //
  // lowest bit cleared, means it is a structure pointer
  // we need 4 bits to represent types

Bit description is off by one bit.