Integration of a Cycle-approximate Model Into a Cycle-accurate Environment

Abstract: Software models can simulate hardware components to varying degrees of ac- curacy. On the extreme ends, there are purely functional models which have no concept of time and execute requests right away, and cycle-accurate models which capture all the implementation details and clock the time they take. In this thesis we study a model of an Arm Mali GPU which is a cycle-approximate model, meaning it is somewhere between the two. The model has some time- keeping abilities, but still accesses data in a functional untimed way. This creates compatibility issues if we want to connect it with cycle-accurate models which expect timed memory requests. To bridge this gap, we implement a scheme to convert untimed requests into timed when needed by employing a scheme of coroutines to switch context until timing requirements can be satisfied. We find that our scheme enables the model to work correctly in an environment that de- mands timed requests, but at the cost of accuracy loss in the model’s performance estimations.