XMSIM: EXtensible Memory SIMulator for Early Memory Hierarchy Evaluation

This paper presents a memory hierarchy evaluation framework for multimedia applications. It takes as input a high level C code application description and a memory hierarchy specification and provides statistics characterizing the memory operation. Essentially the tool is a specialized C++ data type library which is used to replace the application´s data types with others that monitor memory access activity. XMSIM´s operation is event driven which means that every access to a specific data structure is converted to a message towards the memory model which subsequently emulates memory hierarchy operation. The memory model is highly parametric allowing a large number of alternatives to be modeled. XMSIM´s main advantage is its modularity allowing the designer to alter specific aspects of the memory operation beyond the predefined ones. The main features are the capability to: 1) simulate any subset of the application´s data types, 2) user defined mapping of data to memories, 3) simultaneously simulate multiple memory hierarchy scenarios, 4) immediate feedback to code transformations effect on memory hierarchy behavior, 5) verification utilities for the validation of code transformations.