Since its announcement, the IBM RISC System/6000® processor has characterized the aggressive instruction-level parallelism approach to achieving performance. Recent enhancements to the architecture and implementation provide greater superscalar capability. This paper describes the architectural extensions which improve storage reference bandwidth, allow hardware square-root computation, and speed floating-point-to-integer conversion. The implementation, which exploits these extensions and doubles the number of functional units, is also described. A comparison of performance results on a variety of industry standard benchmarks demonstrates that superscalar capabilities are an attractive alternative to aggressive clock rates.
Note: The Institute of Electrical and Electronics Engineers, Incorporated is distributing this Article with permission of the International Business Machines Corporation (IBM) who is the exclusive owner. The recipient of this Article may not assign, sublicense, lease, rent or otherwise transfer, reproduce, prepare derivative works, publicly display or perform, or distribute the Article.