RtlNumberOfClearBits

NTSTATUS __fastcall RtlNumberOfClearBits(UINT64 *a1){
  return *(_DWORD *)a1 - RtlNumberOfSetBits(a1);
}

Referenced by:

PopGetRemainingHibernateRangeDataSize
PopSaveHiberContext
ViThunkCreateSharedExportInformation
ViThunkReplaceAllSharedExports