IopInterlockedAdd

UINT64 __stdcall IopInterlockedAdd(UINT64 *Addend, INT64 Value){
  unsigned __int64 v2; 
  unsigned __int64 v3; 
  __int64 v4; 

  v2 = *Addend;
  do
  {
    v3 = v2;
    v4 = (int)Value + ((v2 >> 1) & 3);
    v2 = _InterlockedCompareExchange64((volatile signed __int64 *)Addend, v2 & 0xFFFFFFFFFFFFFFF9ui64 | (2 * v4), v2);
  }
  while( v3 != v2 );
  return(unsigned int)v4;
}

Referenced by:

IoRemoveIoCompletion
IopCancelIrpsInFileObjectList
IopCheckListForCancelableIrp
IopCompleteRequest
IopDropIrp