Instruction Level Distributed Processing: Adapting to Shifting Technology

Within two or three technology generations, processor architects will face a number of major challenges. Wire delays will become critical, and power considerations will temper the availability of billions of transistors. Many important applications will be object-oriented, multithreaded, and will consist of many separately compiled and dynamically linked parts. To accommodate these shifts in both technology and applications, microarchitectures will process instruction streams in a distributed fashion -instruction level distributed processing (ILDP). ILDP will be implemented in a variety of ways, including both homogeneous and heterogeneous elements. To help find runtime parallelism, orchestrate distributed hardware resources, and implement power conservation strategies, an additional layer of abstraction -the virtual machine layer -will likely become an essential ingredient. Finally, new instruction sets may be necessary to better focus on instruction level communication and dependence, rather than computation and independence as is commonly done today.