Mapping Recursive Functions to Reconfigurable Hardware

Reconfigurable computing devices such as FPGAs offer application developers the ability to create solutions with a performance comparable to that of a hardware solution, but with the flexibility of software. Development tools that attempt to support popular software development languages such as C and Java have been developed to reduce the need for the FPGA developer to be trained in hardware design practices, however the tools have not been successful in mirroring all of the languages functionality. In particular most tools do not support programming with recursive functions. Previous research on mapping recursive functions to reconfigurable hardware has built a stack on the device which does not take full advantage of the massive amount of parallel resources on the reconfigurable device. This paper describes a method for mapping recursive functions to reconfigurable hardware without the use of a stack. It does this by unrolling the function on the device as it is executing. The results presented in this paper show that using this method can result in a significant performance increase when compared to a stack based implementation.