An efficient vector implementation of the FFT algorithm on IBM 3090VF

In this paper, an efficient vector implementation of the fast Fourier transform (FFT) algorithm on the IBM 3090 Vector Facility is presented. This is a part of the Engineering and and Scientific Subroutine Library (ESSL). The implementation works with the full vector length of the machine and the cache is also efficiently managed to achieve very good performance. For short length transforms, a multiple number of transforms could be computed to improve performance. The performance of the vector rountines is compared against state of the art scalar routines and the performance improvements of up to a factor of 8 are observed.