message: Adding required preprocessor directives.
diff: @@ -632,15 +632,19 @@ void BilinearForm::AssembleDiagonal(Vector &diag) const
  Vector local_diag(P->Height());
  ext->AssembleDiagonal(local_diag);
  const SparseMatrix *SP = dynamic_cast<const SparseMatrix*>(P);
  +#ifdef MFEM_USE_MPI
  const HypreParMatrix *HP = dynamic_cast<const HypreParMatrix*>(P);
  +#endif
  if (SP)
  {
  SP->AbsMultTranspose(local_diag, diag);
  }
  +#ifdef MFEM_USE_MPI
  else if (HP)
  {
  HP->AbsMultTranspose(1.0, local_diag, 0.0, diag);
  }
  +#endif
  else
  {
  MFEM_ABORT("Prolongation matrix has unexpected type.");
  