|Topic:||DYNAMO: Transparent Dynamic Optimization|
|Date:||Tuesday, October 19, 1999|
|Place:||Gould-Simpson, Room 701|
Dynamic optimization refers to the runtime optimization of a native program binary. This talk describes the design and implementation of DYNAMO, a prototype dynamic optimizer that is capable of optimizing a native program binary at runtime. DYNAMO is a realistic implementation, not a simulation, that is written entirely in user-level software, and runs on a PA-RISC machine under the HPUX operating system. DYNAMO does not depend on any special programming language, compiler, operating system or hardware support. The program binary is not instrumented and is left untouched during DYNAMO's operation. DYNAMO observes the program's behavior through interpretation to dynamically select hot instruction traces from the running program. The hot traces are optimized using low-overhead optimization techniques and emitted into a software code cache. Subsequent instances of these traces cause the cached version to be executed, resulting in a performance boost. Contrary to intuition, we demonstrate that it is possible to use a piece of software to improve the performance of a native, statically optimized program binary, while it is executing.