The CoGenT project: co-generating compilers and simulators for dynamically compiled languages

To understand the performance of modern Java systems one must observe execution in the context of specific architectures. It is also important that we make these observations using a compiler that is capable of producing optimizations that are specialized to the target machine. Current architectural simulators, however, provide little or no support for dynamically compiled languages and their environments. At the same time, high-quality optimizing compilers lack the flexibility needed to be quickly retargeted to architectural variations. Experimenting with innovative architectural ideas requires modifications not only to the simulator, but to the compiler backend as well. Currently, it is difficult if not impossible to accomplish exploration of this sort. This paper proposes a system for the coordinated effort of generating simulators and matching compiler backends automatically from machine descriptions. Machine descriptions are processed by tools to produce efficient compiler and simulator components and these components "plug in" to an existing framework. This system provides an exploratory environment for compiler writers, computer architects, and students, while maintaining the performance and flexibility required for evaluating real systems.