fix performance issue with SPMV

1 files changed, 11 insertions, 24 deletions

diff --git a/Eigen/src/Sparse/SparseDenseProduct.h b/Eigen/src/Sparse/SparseDenseProduct.h
index dda14bc13..fff97ccd1 100644
--- a/Eigen/src/Sparse/SparseDenseProduct.h
+++ b/Eigen/src/Sparse/SparseDenseProduct.h
@@ -166,42 +166,29 @@ class SparseTimeDenseProduct
       typedef typename internal::remove_all<Lhs>::type _Lhs;
       typedef typename internal::remove_all<Rhs>::type _Rhs;
       typedef typename _Lhs::InnerIterator LhsInnerIterator;
-      enum { LhsIsRowMajor = (_Lhs::Flags&RowMajorBit)==RowMajorBit };
+      enum {
+        LhsIsRowMajor = (_Lhs::Flags&RowMajorBit)==RowMajorBit,
+        RhsIsVector   = Rhs::ColsAtCompileTime==1
+      };
       Index j=0;
-//#pragma omp parallel for private(j) schedule(static,4)
       for(j=0; j<m_lhs.outerSize(); ++j)
       {
-        //kernel(dest,alpha,j);
         typename Rhs::Scalar rhs_j = alpha * m_rhs.coeff(LhsIsRowMajor ? 0 : j,0);
         typename Dest::RowXpr dest_j(dest.row(LhsIsRowMajor ? j : 0));
+        typename Dest::Scalar tmp(0);
         for(LhsInnerIterator it(m_lhs,j); it ;++it)
         {
-          if(LhsIsRowMajor)                   dest_j += (alpha*it.value()) * m_rhs.row(it.index());
-          else if(Rhs::ColsAtCompileTime==1)  dest.coeffRef(it.index()) += it.value() * rhs_j;
-          else                                dest.row(it.index()) += (alpha*it.value()) * m_rhs.row(j);
+          if(LhsIsRowMajor && RhsIsVector)  tmp += (it.value()) * m_rhs.coeff(it.index());
+          else if(LhsIsRowMajor)            dest_j += (alpha*it.value()) * m_rhs.row(it.index());
+          else if(RhsIsVector)              dest.coeffRef(it.index()) += it.value() * rhs_j;
+          else                              dest.row(it.index()) += (alpha*it.value()) * m_rhs.row(j);
         }
+        if(LhsIsRowMajor && RhsIsVector)
+          dest.coeffRef(LhsIsRowMajor ? j : 0) = alpha * tmp;
       }
     }
 
   private:
-    template<typename Dest>
-    EIGEN_DONT_INLINE void kernel(Dest& dest, Scalar alpha, int j) const
-    {
-      typedef typename internal::remove_all<Lhs>::type _Lhs;
-      typedef typename internal::remove_all<Rhs>::type _Rhs;
-      typedef typename _Lhs::InnerIterator LhsInnerIterator;
-      enum { LhsIsRowMajor = (_Lhs::Flags&RowMajorBit)==RowMajorBit };
-      {
-        typename Rhs::Scalar rhs_j = alpha * m_rhs.coeff(LhsIsRowMajor ? 0 : j,0);
-        typename Dest::RowXpr dest_j(dest.row(LhsIsRowMajor ? j : 0));
-        for(LhsInnerIterator it(m_lhs,j); it ;++it)
-        {
-          if(LhsIsRowMajor)                   dest_j += (alpha*it.value()) * m_rhs.row(it.index());
-          else if(Rhs::ColsAtCompileTime==1)  dest.coeffRef(it.index()) += it.value() * rhs_j;
-          else                                dest.row(it.index()) += (alpha*it.value()) * m_rhs.row(j);
-        }
-      }
-    }
     SparseTimeDenseProduct& operator=(const SparseTimeDenseProduct&);
 };