Institute of Mathematics and Informatics Bulgarian Academy of Sciences
Serdica Journal of Computing, Vol. 4, No 3, (2010), 349p-370p
The C++ class library C-XSC for scientific computing has been
extended with the possibility to compute scalar products with selectable accuracy in version 2.3.0. In previous versions, scalar products have always
been computed exactly with the help of the so-called long accumulator. Additionally, optimized floating point computation of matrix and vector operations using BLAS-routines are added in C-XSC version 2.4.0. In this article
the algorithms used and their implementations, as well as some potential
pitfalls in the compilation, are described in more detail. Additionally, the
theoretical background of the employed DotK algorithm and the necessary
modifications of the concrete implementation in C-XSC are briefly explained.
Run-time tests and numerical examples are presented as well.