From 842e31cf5c8fd31f394156ada84a1aeeab89ef7e Mon Sep 17 00:00:00 2001
From: Gael Guennebaud <g.gael@free.fr>
Date: Mon, 29 Sep 2014 13:37:49 +0200
Subject: [PATCH] Let KroneckerProduct exploits the recently introduced generic
 InnerIterator class.

---
 .../KroneckerProduct/KroneckerTensorProduct.h | 33 ++++++-------------
 unsupported/test/kronecker_product.cpp        | 12 +++++++
 2 files changed, 22 insertions(+), 23 deletions(-)

diff --git a/unsupported/Eigen/src/KroneckerProduct/KroneckerTensorProduct.h b/unsupported/Eigen/src/KroneckerProduct/KroneckerTensorProduct.h
index 608c72021..b459360df 100644
--- a/unsupported/Eigen/src/KroneckerProduct/KroneckerTensorProduct.h
+++ b/unsupported/Eigen/src/KroneckerProduct/KroneckerTensorProduct.h
@@ -157,40 +157,27 @@ void KroneckerProductSparse<Lhs,Rhs>::evalTo(Dest& dst) const
   dst.resizeNonZeros(0);
   
   // 1 - evaluate the operands if needed:
-  typedef typename internal::nested_eval<Lhs,10>::type Lhs1;
+  typedef typename internal::nested_eval<Lhs,Dynamic>::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::nested_eval<Rhs,Dynamic>::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;
+    
+  // 2 - construct respective iterators
+  typedef InnerIterator<Lhs1Cleaned> LhsInnerIterator;
+  typedef InnerIterator<Rhs1Cleaned> RhsInnerIterator;
   
   // compute number of non-zeros per innervectors of dst
   {
     VectorXi nnzA = VectorXi::Zero(Dest::IsRowMajor ? m_A.rows() : m_A.cols());
     for (typename Lhs::Index kA=0; kA < m_A.outerSize(); ++kA)
-      for (LhsInnerIterator itA(lhsEval,kA); itA; ++itA)
+      for (LhsInnerIterator itA(lhs1,kA); itA; ++itA)
         nnzA(Dest::IsRowMajor ? itA.row() : itA.col())++;
       
     VectorXi nnzB = VectorXi::Zero(Dest::IsRowMajor ? m_B.rows() : m_B.cols());
     for (typename Rhs::Index kB=0; kB < m_B.outerSize(); ++kB)
-      for (RhsInnerIterator itB(rhsEval,kB); itB; ++itB)
+      for (RhsInnerIterator itB(rhs1,kB); itB; ++itB)
         nnzB(Dest::IsRowMajor ? itB.row() : itB.col())++;
     
     Matrix<int,Dynamic,Dynamic,ColMajor> nnzAB = nnzB * nnzA.transpose();
@@ -201,9 +188,9 @@ void KroneckerProductSparse<Lhs,Rhs>::evalTo(Dest& dst) const
   {
     for (typename Rhs::Index kB=0; kB < m_B.outerSize(); ++kB)
     {
-      for (LhsInnerIterator itA(lhsEval,kA); itA; ++itA)
+      for (LhsInnerIterator itA(lhs1,kA); itA; ++itA)
       {
-        for (RhsInnerIterator itB(rhsEval,kB); itB; ++itB)
+        for (RhsInnerIterator itB(rhs1,kB); itB; ++itB)
         {
           const DestIndex
             i = DestIndex(itA.row() * Br + itB.row()),
diff --git a/unsupported/test/kronecker_product.cpp b/unsupported/test/kronecker_product.cpp
index 753a2d417..02411a262 100644
--- a/unsupported/test/kronecker_product.cpp
+++ b/unsupported/test/kronecker_product.cpp
@@ -216,5 +216,17 @@ void test_kronecker_product()
     sC2 = kroneckerProduct(sA,sB);
     dC = kroneckerProduct(dA,dB);
     VERIFY_IS_APPROX(MatrixXf(sC2),dC);
+    
+    sC2 = kroneckerProduct(dA,sB);
+    dC = kroneckerProduct(dA,dB);
+    VERIFY_IS_APPROX(MatrixXf(sC2),dC);
+    
+    sC2 = kroneckerProduct(sA,dB);
+    dC = kroneckerProduct(dA,dB);
+    VERIFY_IS_APPROX(MatrixXf(sC2),dC);
+    
+    sC2 = kroneckerProduct(2*sA,sB);
+    dC = kroneckerProduct(2*dA,dB);
+    VERIFY_IS_APPROX(MatrixXf(sC2),dC);
   }
 }