Multiple context multithreaded superscalar processor architecture

Superscalar architecture is becoming the norm in todayʹs high performance microprocessor design. However, achievable instruction level parallelism in programs limits the scalability of such architectures. In this paper, we introduce the Multiple Context Multithreaded Superscalar Processor (MCMS), which is an extension of conventional superscalar processor architecture to support multithreading. This is motivated by the enormous potential instruction level parallelism present in multithreaded programs. A hardware implementation of multithreaded constructs is also proposed. Results from trace-driven simulation show that with the MCMS, instruction level parallelism is indeed increased significantly. A MCMS processor with four hardware contexts can produce a speedup of up to 2.5 times over superscalar processor with similar hardware resources. We found that the primary limitation shifts from data dependencies in the superscalar processor to resource contentions in MCMS.