A direct-execution framework for fast and accurate simulation of superscalar processors

Multiprocessor system evaluation has traditionally been based on direct-execution based Execution-Driven Simulations (EDS). In such environments, the processor component of the system is not fully modeled. With wide issue superscalar processors being the norm in today´s multiprocessor nodes, there is an urgent need for modeling the processor accurately. However, using direct execution to model a superscalar processor has been considered an open problem. Hence, current approaches model the processor by interpreting the application executable. Unfortunately, this approach can be slow. In this paper, we propose a novel direct-execution framework that allows accurate simulation of wide-issue superscalar processors without the need for code interpretation. This is achieved with the aid of an Interface Window between the front-end and the architectural simulator, that buffers the necessary information. This eliminates the need for full-fledged instruction emulation. Overall, this approach enables detailed yet fast EDS of superscalar processors. Finally, we evaluate the framework and show good performance for uni- and multiprocessor configurations