Iterative Refinement on FPGAs

Achievable accuracy for mixed precision iterative refinement depends on the precisions supported by computing platforms. Even though the arithmetic unit precision can be flexible for programmable logic computing architectures (e.g. FPGAs), previous work rarely discusses the performance benefits due to enabling flexible achievable accuracy. Hence, we propose an iterative refinement approach on FPGAs which employs an arbitrary precision for the iterative refinement to obtain an arbitrary accuracy. We implement single processing elements for the refinement on the Xilinx XC5VLX110T and compare them to Xilinx XC6VSX475T for performance estimation. This paper shows that the performance is similar to the NVIDIA GTX480 when a user requires accuracies between single and double precision, but the implementation can also produce beyond double precision accuracy.