> Compiled -O3 n a 64-bit Linux box the following code takes 9ms with 2.0.10 and 285ms with 2.0.15
>
> I don't know the hg root to clone the release candidate for 2.0.16 so I haven't checked.
>
> R
>
>
> #include <Eigen/Core>
> #include <Eigen/Array>
>
> int main(){
> int n = 50;
> Eigen::MatrixXd m1(n,n);
> Eigen::MatrixXd m2(n,n);
> Eigen::MatrixXd m3(n,n);
> m1.setRandom();
> m2.setRandom();
> m3.setRandom();
>
> Eigen::VectorXd v1(n);
> Eigen::VectorXd v2(n);
> Eigen::VectorXd v3(n);
> v1.setRandom();
> v2.setRandom();
> v3.setRandom();
>
> for (int i = 0; i != 100; ++i) {
> v3 = m1*(m2*v1+m3.transpose()*m2*v2);
> }
>
> return 0;
> }
>
>
>
>