Experiences with Dynamic Binary Translation in a Full System Simulator

In this paper we describe our experiences with a new full-system simulator for the Power™ architecture that achieves a high-level of simulation performance through careful design and the application of dynamic binary translation. Our simulator is written entirely in Java and can run simple applications and also boot whole operating systems. We chose Java because it has a wide developer base, portability, support for modern programming features such as inheritance, ease of scripting, built in serialization, and a broad selection of robust developer tools. To improve simulation performance, we treat the byte code for our instruction interpreter as an intermediate representation to drive dynamic binary translation. When running as a pure instruction interpreter, the simulator can achieve simulation speeds of over 100 MIPS. For simple applications, dynamic binary translation can improve simulation performance by a factor of 2 or more, to over 200 MIPS. We continue to work on dynamic binary translation for booting a full operating system, and we are also exploring dynamic translation of Java byte code directly to host object code.