A unified vector/scalar floating-point architecture

Abstract

In this paper we present a unified approach to vector and scalar computation, using a single register file for both scalar operands and vector elements. The goal of this architecture is to yield improved scalar performance while broadening the range of vectorizable applications. For example, reduction operations and recurrences can be expressed in vector form in this architecture. This approach results in greater overall performance for most applications than does the approach of emphasizing peak vector performance. The hardware required to support the enhanced vector capability is insignificant, but allows the execution of two operations per cycle for vectorized code. Moreover, the size of the unified vector/scalar register file required for peak performance is an order of magnitude smaller than traditional vector register files, allowing efficient on-chip VLSI implementation. The results of simulations of the Livermore Loops and Linpack using this architecture are presented.