Restructuring the BLAS level 1 routine for computing the modified givens transformation

Abstract

We look at how both logical restructuring and improvements available from successive versions of Fortran allow us to reduce the complexity (measured by a number of the commonly used software metrics) of the Level 1 BLAS code used to compute the modified Givens transformation. With these reductions in complexity we claim that we have improved both the maintainability and clarity of the code; in addition, we report a fix to a minor problem with the original code. The performance of two commercial Fortran restructuring tools is also reported.