From b2b8c1d41efac41775cf64b6c39d2cabde9c59f7 Mon Sep 17 00:00:00 2001
From: Gael Guennebaud <g.gael@free.fr>
Date: Tue, 29 Sep 2015 11:11:40 +0200
Subject: [PATCH] Fix performance regression in sparse * dense product where
 "sparse" is an expression

---
 Eigen/src/SparseCore/SparseDenseProduct.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/Eigen/src/SparseCore/SparseDenseProduct.h b/Eigen/src/SparseCore/SparseDenseProduct.h
index 67b3c9c1b..3710e05a6 100644
--- a/Eigen/src/SparseCore/SparseDenseProduct.h
+++ b/Eigen/src/SparseCore/SparseDenseProduct.h
@@ -160,8 +160,8 @@ struct generic_product_impl<Lhs, Rhs, SparseShape, DenseShape, ProductType>
   template<typename Dest>
   static void scaleAndAddTo(Dest& dst, const Lhs& lhs, const Rhs& rhs, const Scalar& alpha)
   {
-    typedef typename nested_eval<Lhs,Dynamic>::type LhsNested;
-    typedef typename nested_eval<Rhs,Dynamic>::type RhsNested;
+    typedef typename nested_eval<Lhs,((Rhs::Flags&RowMajorBit)==0) ? 1 : Rhs::ColsAtCompileTime>::type LhsNested;
+    typedef typename nested_eval<Rhs,((Lhs::Flags&RowMajorBit)==0) ? 1 : Dynamic>::type RhsNested;
     LhsNested lhsNested(lhs);
     RhsNested rhsNested(rhs);
     internal::sparse_time_dense_product(lhsNested, rhsNested, dst, alpha);
@@ -182,8 +182,8 @@ struct generic_product_impl<Lhs, Rhs, DenseShape, SparseShape, ProductType>
   template<typename Dst>
   static void scaleAndAddTo(Dst& dst, const Lhs& lhs, const Rhs& rhs, const Scalar& alpha)
   {
-    typedef typename nested_eval<Lhs,Dynamic>::type LhsNested;
-    typedef typename nested_eval<Rhs,Dynamic>::type RhsNested;
+    typedef typename nested_eval<Lhs,((Rhs::Flags&RowMajorBit)==0) ? Dynamic : 1>::type LhsNested;
+    typedef typename nested_eval<Rhs,((Lhs::Flags&RowMajorBit)==RowMajorBit) ? 1 : Lhs::RowsAtCompileTime>::type RhsNested;
     LhsNested lhsNested(lhs);
     RhsNested rhsNested(rhs);