Programming in VS Fortran on the IBM 3090 for maximum vector performance

Programming techniques necessary for high performance on the 3090 Vector Facilities are illustrated, showing that VS Fortran programs can achieve near-maximum execution rates. Relevant features of the 3090 architecture are reviewed, stressing the need to make efficient use of a hierarchical storage system and take advantage of the compound vector instructions. The key programming techniques for managing the storage hierarchy are loop sectioning, loop distribution, and data compaction. Vector register, cache reuse, and virtual memory, storage format, and page reuse are shown to lead to efficient use of the vector registers, the high speed cache, and the virtual memory system, respectively. The multiply-and-add compound instruction is discussed.<>