Improving Large Vector Operations with C++ Expression Template and ATLAS

This paper describes a short and simple way of improving the performance of vector operations (e.g. X = aY + bZ + ..) applied to large vectors. The principle is to take advantage of high performance vector copy operation provided by the ATLAS library [1] used as a kernel for a C++ Expression Template (ET) mechanism. The proposed ET implementation that involves a simple blocking technique, leads to significant performance increase compared to existing implementations (up to 50%) and extends the ATLAS scope.