Dynamic optimization is emerging as a promising approach to overcome many of the obstacles of traditional static compilation. But while there are a number of compiler infrastructures for developing static optimizations, there are very few for developing dynamic optimizations. We present a framework for implementing dynamic analyses and optimizations. We provide an interface for building external modules, or clients, for the DynamoRIO dynamic code modification system. This interface abstracts away many low-level details of the DynamoRIO runtime system while exposing a simple and powerful, yet efficient and lightweight, API. This is achieved by restricting optimization units to linear streams of code and using adaptive levels of detail for representing instructions. The interface is not restricted to optimization and can be used for instrumentation, profiling, dynamic translation, etc.. To demonstrate

For domain specific languages, "scripting languages", dynamic languages, and for virtual machine-based languages, the most straightforward implementation strategy is to write an interpreter. A simple interpreter consists of a loop that fetches the next bytecode, dispatches to the routine handling that bytecode, then loops. There are many ways to improve upon this simple mechanism, but as long as the execution of the program is driven by a representation of the program other than as a stream of native instructions, there will be some "interpretive overhead".

this paper: to provide a rough classification of the numerous approaches in program analysis---especially in dynamic analysis---, to show their common benefits and limits, and to show up new research directions to overcome these limits

We present the DeAL language for heap assertions that are efficiently evaluated during garbage collection time. DeAL is a rich, declarative, logic-based language whose programs are guaranteed to be executable with good whole-heap locality, i.e., within a single traversal over every live object on the heap and a finite neighborhood around each object. As a result, evaluating DeAL programs incurs negligible cost: for simple assertion checking at each garbage collection, the end-to-end execution slowdown is below 2%. DeAL is integrated into Java as a VM extension and we demonstrate its efficiency and expressiveness with several applications and properties from the past literature. Compared to past systems for heap assertions, DeAL is distinguished by its very attractive expressiveness/efficiency tradeoff: it offers a significantly richer class of assertions than what past systems could check with a single traversal. Conversely, past systems that can express the same (or more) complex assertions as DeAL do so only by suffering ordersof-magnitude higher costs. 1.