int CCTK_Reduce1(const cGH *GH,
                 int proc,
                 int operation_handle,
                 int num_out_vals,
                 int type_out_vals,
                 void *out_vals,
                 int num_in_fields,
                 const int *in_fields)
{
  int retval;
  t_reduce_operator *operator;

  /* Get the pointer to the reduction operator */
  if (operation_handle < 0)
  {
    CCTK_Warn(3,__LINE__,__FILE__,"Cactus",
              "CCTK_Reduce1: Invalid handle passed to CCTK_Reduce1");
    retval = -1;
  }
  else
  {
    operator = Util_GetHandledData(ReductionOperators,operation_handle);

    if (!operator)
    {
      CCTK_Warn(3,__LINE__,__FILE__,"Cactus",
                "CCTK_Reduce1: Reduction operation is not registered"
                "and cannot be called");
      retval = -1;
    }
    else
    {
      retval = operator->reduce_operator (GH, proc, num_out_vals,
                                          type_out_vals, out_vals,
                                          num_in_fields, in_fields);
    }
  }
  return retval;
}

void CCTK_FCALL CCTK_FNAME(CCTK_Reduce1)
     (int *fortranreturn,
      const cGH *const *GH,
      const int *proc,
      const int *operation_handle,
      const int *num_out_vals,
      const int *type_out_vals,
      void *out_vals,
      const int *num_in_fields,
      const int *in_fields)
{
  *fortranreturn =
    CCTK_Reduce1(*GH, *proc, *operation_handle,
                 *num_out_vals, *type_out_vals, out_vals,
                 *num_in_fields, in_fields);
}