Code patterns in Kokkos enabled Albany

1. Replace PHX::TypeString::value with PHX::typeAsString();

Example:

 this->setName("Gather Solution"+PHX::TypeString<EvalT>::value);

should be replaced with

 this->setName("Gather Solution"+PHX::typeAsString<EvalT>());

2. MDField no longer has operator[].

   for (std::size_t i=0; i < Residual.size(); ++i) Residual[i]=0.0

should be replaced with

 Residual.deep_copy(0.0); 

or

 for (int i=0; i<Residual.dimension(0); i++)
    for (int j=0; j<Residual.dimension(1); j++)
      Residual(i,j)=0.0;

or

for (PHAL::MDFieldIterator<ScalarT> gr(Residual); ! gr.done(); ++gr)
   *gr = 0.0;

3. We can't use pointers with Kokkos data types, so we need to replace pointer usage with direct access

Example 1:

    MeshScalarT* X = &coordVec(cell,qp,0);
    f[0] =  40.0*muqp*(2.0*X[1]*X[1] - 3.0*X[1]+1.0)*X[1]*(6.0*X[0]*X[0] -6.0*X[0] + 1.0)
           + 120*muqp*(X[0]-1.0)*(X[0]-1.0)*X[0]*X[0]*(2.0*X[1]-1.0) 

could be replaced with

    typename PHAL::Ref<MeshScalarT>::type X0 = coordVec(cell,qp,0);
    typename PHAL::Ref<MeshScalarT>::type X1 = coordVec(cell,qp,1);
    force(cell,qp,0) =  40.0*muqp*(2.0*X1*X1 - 3.0*X1+1.0)*X1*(6.0*X0*X0 -6.0*X0 + 1.0)
                     + 120*muqp*(X0-1.0)*(X0-1.0)*X0*X0*(2.0*X1-1.0) 

Example 2:

    if (this->tensorRank == 2)       valptr = this->valTensor[0](cell,node,eq/numDim,eq%numDim);
    else if (this->tensorRank == 1)  valptr = this->valVec[0](cell,node,eq);
    else                             valptr = this->val[eq](cell,node);

could be replaced with

    typename PHAL::Ref<ScalarT>::type valptr =
       (this->tensorRank == 2) ? this->valTensor[0](cell,node,eq/numDim,eq%numDim) :
       (this->tensorRank == 1) ? this->valVec[0](cell,node,eq) :
                                 this->val[eq](cell,node);

In these examples, the syntax typename PHAL::Ref<ScalarT>::type evaluates to a type that is semantically like a reference. If ScalarT is a POD, then it is a reference; if it is a FadType, for example, then it is a Kokkos::View.

4. MiniTensor changes:

   Tensor B(*A(i,j,0,0)); B.fill (*C(i,j,0,0));

   should be replaced with:

   Tensor B(*A,i,j,0,0); B.fill (*C,i,j,0,0);

5. Teuchos::reduceAll calls on MDFields should be changed. For example, this code:

Teuchos::RCP< Teuchos::ValueTypeSerializer<int,ScalarT> > serializer =
  workset.serializerManager.template getValue<EvalT>();
Teuchos::reduceAll(
  *workset.comm, *serializer, Teuchos::REDUCE_SUM,
  this->global_response.size(), &this->global_response[0], 
  &this->global_response[0]);

becomes

PHAL::reduceAll<ScalarT>(*workset.comm, Teuchos::REDUCE_SUM,
                         this->global_response);