From 2ae20d558b33653b8ef2fe17255ed171997bcf79 Mon Sep 17 00:00:00 2001
From: Gael Guennebaud <g.gael@free.fr>
Date: Thu, 18 Sep 2014 22:08:49 +0200
Subject: [PATCH] Update KroneckerProduct wrt evaluator changes

---
 .../KroneckerProduct/KroneckerTensorProduct.h | 36 +++++++++++++++----
 unsupported/test/CMakeLists.txt               |  2 +-
 2 files changed, 31 insertions(+), 7 deletions(-)

diff --git a/unsupported/Eigen/src/KroneckerProduct/KroneckerTensorProduct.h b/unsupported/Eigen/src/KroneckerProduct/KroneckerTensorProduct.h
index ca66d4d89..72e25db19 100644
--- a/unsupported/Eigen/src/KroneckerProduct/KroneckerTensorProduct.h
+++ b/unsupported/Eigen/src/KroneckerProduct/KroneckerTensorProduct.h
@@ -154,16 +154,41 @@ void KroneckerProductSparse<Lhs,Rhs>::evalTo(Dest& dst) const
   dst.resize(this->rows(), this->cols());
   dst.resizeNonZeros(0);
   
+  // 1 - evaluate the operands if needed:
+  typedef typename internal::nested_eval<Lhs,10>::type Lhs1;
+  typedef typename internal::remove_all<Lhs1>::type Lhs1Cleaned;
+  const Lhs1 lhs1(m_A);
+  typedef typename internal::nested_eval<Rhs,10>::type Rhs1;
+  typedef typename internal::remove_all<Rhs1>::type Rhs1Cleaned;
+  const Rhs1 rhs1(m_B);
+  
+  // 2 - construct a SparseView for dense operands
+  typedef typename internal::conditional<internal::is_same<typename internal::traits<Lhs1Cleaned>::StorageKind,Sparse>::value, Lhs1, SparseView<const Lhs1Cleaned> >::type Lhs2;
+  typedef typename internal::remove_all<Lhs2>::type Lhs2Cleaned;
+  const Lhs2 lhs2(lhs1);
+  typedef typename internal::conditional<internal::is_same<typename internal::traits<Rhs1Cleaned>::StorageKind,Sparse>::value, Rhs1, SparseView<const Rhs1Cleaned> >::type Rhs2;
+  typedef typename internal::remove_all<Rhs2>::type Rhs2Cleaned;
+  const Rhs2 rhs2(rhs1);
+  
+  // 3 - construct respective evaluators
+  typedef typename internal::evaluator<Lhs2Cleaned>::type LhsEval;
+  LhsEval lhsEval(lhs2);
+  typedef typename internal::evaluator<Rhs2Cleaned>::type RhsEval;
+  RhsEval rhsEval(rhs2);
+  
+  typedef typename LhsEval::InnerIterator LhsInnerIterator;
+  typedef typename RhsEval::InnerIterator RhsInnerIterator;
+  
   // compute number of non-zeros per innervectors of dst
   {
     VectorXi nnzA = VectorXi::Zero(Dest::IsRowMajor ? m_A.rows() : m_A.cols());
     for (Index kA=0; kA < m_A.outerSize(); ++kA)
-      for (typename Lhs::InnerIterator itA(m_A,kA); itA; ++itA)
+      for (LhsInnerIterator itA(lhsEval,kA); itA; ++itA)
         nnzA(Dest::IsRowMajor ? itA.row() : itA.col())++;
       
     VectorXi nnzB = VectorXi::Zero(Dest::IsRowMajor ? m_B.rows() : m_B.cols());
     for (Index kB=0; kB < m_B.outerSize(); ++kB)
-      for (typename Rhs::InnerIterator itB(m_B,kB); itB; ++itB)
+      for (RhsInnerIterator itB(rhsEval,kB); itB; ++itB)
         nnzB(Dest::IsRowMajor ? itB.row() : itB.col())++;
     
     Matrix<int,Dynamic,Dynamic,ColMajor> nnzAB = nnzB * nnzA.transpose();
@@ -174,9 +199,9 @@ void KroneckerProductSparse<Lhs,Rhs>::evalTo(Dest& dst) const
   {
     for (Index kB=0; kB < m_B.outerSize(); ++kB)
     {
-      for (typename Lhs::InnerIterator itA(m_A,kA); itA; ++itA)
+      for (LhsInnerIterator itA(lhsEval,kA); itA; ++itA)
       {
-        for (typename Rhs::InnerIterator itB(m_B,kB); itB; ++itB)
+        for (RhsInnerIterator itB(rhsEval,kB); itB; ++itB)
         {
           const Index i = itA.row() * Br + itB.row(),
                       j = itA.col() * Bc + itB.col();
@@ -201,8 +226,7 @@ struct traits<KroneckerProduct<_Lhs,_Rhs> >
     Rows = size_at_compile_time<traits<Lhs>::RowsAtCompileTime, traits<Rhs>::RowsAtCompileTime>::ret,
     Cols = size_at_compile_time<traits<Lhs>::ColsAtCompileTime, traits<Rhs>::ColsAtCompileTime>::ret,
     MaxRows = size_at_compile_time<traits<Lhs>::MaxRowsAtCompileTime, traits<Rhs>::MaxRowsAtCompileTime>::ret,
-    MaxCols = size_at_compile_time<traits<Lhs>::MaxColsAtCompileTime, traits<Rhs>::MaxColsAtCompileTime>::ret,
-    CoeffReadCost = Lhs::CoeffReadCost + Rhs::CoeffReadCost + NumTraits<Scalar>::MulCost
+    MaxCols = size_at_compile_time<traits<Lhs>::MaxColsAtCompileTime, traits<Rhs>::MaxColsAtCompileTime>::ret
   };
 
   typedef Matrix<Scalar,Rows,Cols> ReturnType;
diff --git a/unsupported/test/CMakeLists.txt b/unsupported/test/CMakeLists.txt
index 7e2186d2d..04863a9ad 100644
--- a/unsupported/test/CMakeLists.txt
+++ b/unsupported/test/CMakeLists.txt
@@ -93,7 +93,7 @@ ei_add_test(gmres)
 ei_add_test(minres)
 ei_add_test(levenberg_marquardt)
 ei_add_test(bdcsvd)
-# TODO ei_add_test(kronecker_product)
+ei_add_test(kronecker_product)
 
 option(EIGEN_TEST_CXX11 "Enable testing of C++11 features (e.g. Tensor module)." OFF)
 if(EIGEN_TEST_CXX11)