Vectorization of N-body codes.

We have prepared a cosmological N-body code based on the Ahmad-Cohen method for vectorization on the FACOM VP-200 vector processor. The modifications are relatively simple, leaving the main algorithms essentially unchanged. Comparison with the scalar version shows an overall gain in speed of the particle integration exceeding a factor of 10 for test calculations with N=4000 particles. Similar principles can readily be applied to more complicated codes including two-body regularization, although the net gain will be somewhat less. [ABSTRACT FROM AUTHOR]