INSTRUCTION ISSUE LOGIC FOR HIGH-PERFORMANCE,

The performance of pipelined processors is severely limited by data dependencies. In order to achieve high performance, a mechanism to alleviate the effects of data dependencies must exist. If a pipelined CPU with multiple func-tional units is to be used in the presence of a vir-tual memory hierarchy, a mechanism must also exist for determining the state of the machine precisely. In this paper, we combine the issues of dependency-resolution and preciseness of state. We present a design for instruction issue logic that resolves dependencies dynamically and, at the same time, guarantees a precise state of the machine, without a significant hardware overhead. Detailed simulation studies for the proposed mechanism, using the Lawrence Livermore loops as a benchmark, are presented. 1