KeSaveLegacyFloatingPointControlWord

NTSTATUS __stdcall KeSaveLegacyFloatingPointControlWord(
        PVOID IoCompletionHandle,
        PVOID KeyContext,
        PVOID ApcContext,
        INT64 IoStatus,
        UINT64 IoStatusInformation){
  NTSTATUS result; 
  __asm { fnclex }
  return result;
}

Referenced by:

KiCaptureUmsThreadContext
KiSwapToUmsThread