Due to the need for fast design cycles and low production cost, programmable targets like DSP processors are becoming increasingly popular. Design planning, detailed design as well as updating such designs requires mapping existing algorithms onto these targets. Instead of writing target-speci c mappers, we propose using retargetable mappers. The technique reported in this paper is based on pattern matching. Binary code is generated as a result of this matching process. This paper describes the techniques of our mapper MSSV and identi es areas for improvements. As a result, it shows that e cient handling of alternative mappings is crucial for an acceptable performance. 1

Introduction P. Marwedel 1 New, flexible target technologies As the tendency towards more complex electronic systems continues, many of these systems are equipped with embedded processors. For example, such processors can be found in cars, and in audio-, video-, and telecommunication-equipment. Essential advantages of these processors include their high flexibility, short design time and (in the case of off-the-shelf processors) full-custom layout quality. Furthermore, they allow an easy implementation of optional product features as well as easy design correction and upgrading. Furthermore, processors are frequently used in cases where the systems must be extremely dependable 1 [32]. In such cases, the re-use of the design of an off-the-shelf processor greatly simplifies dependability analysis. This contrasts with the limitations of application-specific circuits (ASICs): due to their low flexibility, the cost for the desig