diff --git a/Eigen/src/Core/DiagonalMatrix.h b/Eigen/src/Core/DiagonalMatrix.h
index f7ac22f8b..8df636928 100644
--- a/Eigen/src/Core/DiagonalMatrix.h
+++ b/Eigen/src/Core/DiagonalMatrix.h
@@ -66,6 +66,7 @@ class DiagonalBase : public EigenBase<Derived>
     EIGEN_DEVICE_FUNC
     inline Index cols() const { return diagonal().size(); }
 
+#ifndef EIGEN_TEST_EVALUATORS
     /** \returns the diagonal matrix product of \c *this by the matrix \a matrix.
       */
     template<typename MatrixDerived>
@@ -75,6 +76,15 @@ class DiagonalBase : public EigenBase<Derived>
     {
       return DiagonalProduct<MatrixDerived, Derived, OnTheLeft>(matrix.derived(), derived());
     }
+#else
+    template<typename MatrixDerived>
+    EIGEN_DEVICE_FUNC
+    const Product<Derived,MatrixDerived,LazyProduct>
+    operator*(const MatrixBase<MatrixDerived> &matrix) const
+    {
+      return Product<Derived, MatrixDerived, LazyProduct>(derived(),matrix.derived());
+    }
+#endif // EIGEN_TEST_EVALUATORS
 
     EIGEN_DEVICE_FUNC
     inline const DiagonalWrapper<const CwiseUnaryOp<internal::scalar_inverse_op<Scalar>, const DiagonalVectorType> >
@@ -270,7 +280,8 @@ struct traits<DiagonalWrapper<_DiagonalVectorType> >
     ColsAtCompileTime = DiagonalVectorType::SizeAtCompileTime,
     MaxRowsAtCompileTime = DiagonalVectorType::SizeAtCompileTime,
     MaxColsAtCompileTime = DiagonalVectorType::SizeAtCompileTime,
-    Flags =  traits<DiagonalVectorType>::Flags & LvalueBit
+    Flags =  traits<DiagonalVectorType>::Flags & LvalueBit,
+    CoeffReadCost = traits<_DiagonalVectorType>::CoeffReadCost
   };
 };
 }
@@ -341,6 +352,29 @@ bool MatrixBase<Derived>::isDiagonal(const RealScalar& prec) const
   return true;
 }
 
+#ifdef EIGEN_ENABLE_EVALUATORS
+namespace internal {
+  
+// TODO currently a diagonal expression has the form DiagonalMatrix<> or DiagonalWrapper
+//      in the future diagonal-ness should be defined by the expression traits
+template<typename _Scalar, int SizeAtCompileTime, int MaxSizeAtCompileTime>
+struct evaluator_traits<DiagonalMatrix<_Scalar,SizeAtCompileTime,MaxSizeAtCompileTime> >
+{
+  typedef typename storage_kind_to_evaluator_kind<Dense>::Kind Kind;
+  typedef DiagonalShape Shape;
+  static const int AssumeAliasing = 0;
+};
+template<typename Derived>
+struct evaluator_traits<DiagonalWrapper<Derived> >
+{
+  typedef typename storage_kind_to_evaluator_kind<typename Derived::StorageKind>::Kind Kind;
+  typedef DiagonalShape Shape;
+  static const int AssumeAliasing = 0;
+};
+
+} // namespace internal
+#endif // EIGEN_ENABLE_EVALUATORS
+
 } // end namespace Eigen
 
 #endif // EIGEN_DIAGONALMATRIX_H
diff --git a/Eigen/src/Core/ProductEvaluators.h b/Eigen/src/Core/ProductEvaluators.h
index 2279ec33b..d991ff8b5 100644
--- a/Eigen/src/Core/ProductEvaluators.h
+++ b/Eigen/src/Core/ProductEvaluators.h
@@ -309,9 +309,9 @@ struct generic_product_impl<Lhs,Rhs,DenseShape,DenseShape,CoeffBasedProductMode>
 };
 
 // This specialization enforces the use of a coefficient-based evaluation strategy
-// template<typename Lhs, typename Rhs>
-// struct generic_product_impl<Lhs,Rhs,DenseShape,DenseShape,LazyCoeffBasedProductMode>
-//   : generic_product_impl<Lhs,Rhs,DenseShape,DenseShape,CoeffBasedProductMode> {};
+template<typename Lhs, typename Rhs>
+struct generic_product_impl<Lhs,Rhs,DenseShape,DenseShape,LazyCoeffBasedProductMode>
+  : generic_product_impl<Lhs,Rhs,DenseShape,DenseShape,CoeffBasedProductMode> {};
 
 // Case 2: Evaluate coeff by coeff
 //
@@ -764,6 +764,146 @@ protected:
   PlainObject m_result;
 };
 
+/***************************************************************************
+* Diagonal products
+***************************************************************************/
+  
+template<typename MatrixType, typename DiagonalType, typename Derived>
+struct diagonal_product_evaluator_base
+  : evaluator_base<Derived>
+{
+   typedef typename MatrixType::Index Index;
+   typedef typename MatrixType::Scalar Scalar;
+   typedef typename MatrixType::PacketScalar PacketScalar;
+public:
+  diagonal_product_evaluator_base(const MatrixType &mat, const DiagonalType &diag)
+    : m_diagImpl(diag), m_matImpl(mat)
+  {
+  }
+  
+  EIGEN_STRONG_INLINE const Scalar coeff(Index idx) const
+  {
+    return m_diagImpl.coeff(idx) * m_matImpl.coeff(idx);
+  }
+  
+protected:
+  template<int LoadMode>
+  EIGEN_STRONG_INLINE PacketScalar packet_impl(Index row, Index col, Index id, internal::true_type) const
+  {
+    return internal::pmul(m_matImpl.template packet<LoadMode>(row, col),
+                          internal::pset1<PacketScalar>(m_diagImpl.coeff(id)));
+  }
+  
+  template<int LoadMode>
+  EIGEN_STRONG_INLINE PacketScalar packet_impl(Index row, Index col, Index id, internal::false_type) const
+  {
+    enum {
+      InnerSize = (MatrixType::Flags & RowMajorBit) ? MatrixType::ColsAtCompileTime : MatrixType::RowsAtCompileTime,
+      DiagonalPacketLoadMode = (LoadMode == Aligned && (((InnerSize%16) == 0) || (int(DiagonalType::Flags)&AlignedBit)==AlignedBit) ? Aligned : Unaligned)
+    };
+    return internal::pmul(m_matImpl.template packet<LoadMode>(row, col),
+                          m_diagImpl.template packet<DiagonalPacketLoadMode>(id));
+  }
+  
+  typename evaluator<DiagonalType>::nestedType m_diagImpl;
+  typename evaluator<MatrixType>::nestedType   m_matImpl;
+};
+
+// diagonal * dense
+template<typename Lhs, typename Rhs, int ProductKind, int ProductTag>
+struct product_evaluator<Product<Lhs, Rhs, ProductKind>, ProductTag, DiagonalShape, DenseShape, typename Lhs::Scalar, typename Rhs::Scalar> 
+  : diagonal_product_evaluator_base<Rhs, typename Lhs::DiagonalVectorType, Product<Lhs, Rhs, LazyProduct> >
+{
+  typedef diagonal_product_evaluator_base<Rhs, typename Lhs::DiagonalVectorType, Product<Lhs, Rhs, LazyProduct> > Base;
+  using Base::m_diagImpl;
+  using Base::m_matImpl;
+  using Base::coeff;
+  using Base::packet_impl;
+  typedef typename Base::Scalar Scalar;
+  typedef typename Base::Index Index;
+  typedef typename Base::PacketScalar PacketScalar;
+  
+  typedef Product<Lhs, Rhs, ProductKind> XprType;
+  typedef typename XprType::PlainObject PlainObject;
+
+  product_evaluator(const XprType& xpr)
+    : Base(xpr.rhs(), xpr.lhs().diagonal())
+  {
+  }
+  
+  EIGEN_STRONG_INLINE const Scalar coeff(Index row, Index col) const
+  {
+    return m_diagImpl.coeff(row) * m_matImpl.coeff(row, col);
+  }
+  
+  template<int LoadMode>
+  EIGEN_STRONG_INLINE PacketScalar packet(Index row, Index col) const
+  {
+    enum {
+      StorageOrder = Rhs::Flags & RowMajorBit ? RowMajor : ColMajor
+    };
+    return this->template packet_impl<LoadMode>(row,col, row,
+                                 typename internal::conditional<int(StorageOrder)==RowMajor, internal::true_type, internal::false_type>::type());
+  }
+  
+  template<int LoadMode>
+  EIGEN_STRONG_INLINE PacketScalar packet(Index idx) const
+  {
+    enum {
+      StorageOrder = int(Rhs::Flags) & RowMajorBit ? RowMajor : ColMajor
+    };
+    return packet<LoadMode>(int(StorageOrder)==ColMajor?idx:0,int(StorageOrder)==ColMajor?0:idx);
+  }
+  
+};
+
+// dense * diagonal
+template<typename Lhs, typename Rhs, int ProductKind, int ProductTag>
+struct product_evaluator<Product<Lhs, Rhs, ProductKind>, ProductTag, DenseShape, DiagonalShape, typename Lhs::Scalar, typename Rhs::Scalar> 
+  : diagonal_product_evaluator_base<Lhs, typename Rhs::DiagonalVectorType, Product<Lhs, Rhs, LazyProduct> >
+{
+  typedef diagonal_product_evaluator_base<Lhs, typename Rhs::DiagonalVectorType, Product<Lhs, Rhs, LazyProduct> > Base;
+  using Base::m_diagImpl;
+  using Base::m_matImpl;
+  using Base::coeff;
+  using Base::packet_impl;
+  typedef typename Base::Scalar Scalar;
+  typedef typename Base::Index Index;
+  typedef typename Base::PacketScalar PacketScalar;
+  
+  typedef Product<Lhs, Rhs, ProductKind> XprType;
+  typedef typename XprType::PlainObject PlainObject;
+
+  product_evaluator(const XprType& xpr)
+    : Base(xpr.lhs(), xpr.rhs().diagonal())
+  {
+  }
+  
+  EIGEN_STRONG_INLINE const Scalar coeff(Index row, Index col) const
+  {
+    return m_matImpl.coeff(row, col) * m_diagImpl.coeff(col);
+  }
+  
+  template<int LoadMode>
+  EIGEN_STRONG_INLINE PacketScalar packet(Index row, Index col) const
+  {
+    enum {
+      StorageOrder = Rhs::Flags & RowMajorBit ? RowMajor : ColMajor
+    };
+    return this->template packet_impl<LoadMode>(row,col, col,
+                                 typename internal::conditional<int(StorageOrder)==ColMajor, internal::true_type, internal::false_type>::type());
+  }
+  
+  template<int LoadMode>
+  EIGEN_STRONG_INLINE PacketScalar packet(Index idx) const
+  {
+    enum {
+      StorageOrder = int(Rhs::Flags) & RowMajorBit ? RowMajor : ColMajor
+    };
+    return packet<LoadMode>(int(StorageOrder)==ColMajor?idx:0,int(StorageOrder)==ColMajor?0:idx);
+  }
+  
+};
 
 } // end namespace internal
 
diff --git a/test/evaluators.cpp b/test/evaluators.cpp
index 69a45661f..305047a6a 100644
--- a/test/evaluators.cpp
+++ b/test/evaluators.cpp
@@ -151,19 +151,19 @@ void test_evaluators()
     c = a*a;
     copy_using_evaluator(a, prod(a,a));
     VERIFY_IS_APPROX(a,c);
-    
+
     // check compound assignment of products
     d = c;
     add_assign_using_evaluator(c.noalias(), prod(a,b));
     d.noalias() += a*b;
     VERIFY_IS_APPROX(c, d);
-    
+
     d = c;
     subtract_assign_using_evaluator(c.noalias(), prod(a,b));
     d.noalias() -= a*b;
     VERIFY_IS_APPROX(c, d);
   }
-  
+
   {
     // test product with all possible sizes
     int s = internal::random<int>(1,100);
@@ -458,4 +458,15 @@ void test_evaluators()
     VERIFY_IS_APPROX_EVALUATOR2(B, prod(A.selfadjointView<Upper>(),A), MatrixXd(A.selfadjointView<Upper>()*A));
     
   }
+
+  {
+    // test diagonal shapes
+    VectorXd d = VectorXd::Random(6);
+    MatrixXd A = MatrixXd::Random(6,6), B(6,6);
+    A.setRandom();B.setRandom();
+    
+    VERIFY_IS_APPROX_EVALUATOR2(B, lazyprod(d.asDiagonal(),A), MatrixXd(d.asDiagonal()*A));
+    VERIFY_IS_APPROX_EVALUATOR2(B, lazyprod(A,d.asDiagonal()), MatrixXd(A*d.asDiagonal()));
+    
+  }
 }