SimpleScalar: an infrastructure for computer system modeling

Designers can execute programs on software models to validate a proposed hardware design's performance and correctness, while programmers can use these models to develop and test software before the real hardware becomes available. Three critical requirements drive the implementation of a software model: performance, flexibility, and detail. Performance determines the amount of workload the model can exercise given the machine resources available for simulation. Flexibility indicates how well the model is structured to simplify modification, permitting design variants or even completely different designs to be modeled with ease. Detail defines the level of abstraction used to implement the model's components. The SimpleScalar tool set provides an infrastructure for simulation and architectural modeling. It can model a variety of platforms ranging from simple unpipelined processors to detailed dynamically scheduled microarchitectures with multiple-level memory hierarchies. SimpleScalar simulators reproduce computing device operations by executing all program instructions using an interpreter. The tool set's instruction interpreters also support several popular instruction sets, including Alpha, PPC, x86, and ARM.

Modeling Basics

The typical approach to computer system modeling leverages a simple approximate model with good simulation performance and a modular code structure. This simulator style suits researchers and instructors well because the simple model focuses on the design's primary components, leaving out the minutiae of detail that might otherwise hinder the model's performance and flexibility. Industrial users, on the other hand, require very detailed models to minimize design risk. Detailed modeling assures that a design has no faulty components or acute performance bottlenecks.