Reed-Solomon codes are an important class of error correcting codes used in many applications related to communications and digital storage. The fundamental operations in Reed-Solomon encoding and decoding involve Galois field arithmetic which is not directly supported in general purpose processors. On the other hand, pure hardware implementations of Reed-Solomon coders are not programmable. In this paper, we present a novel algorithm to performReed-Solomon encoding. We also propose four new instructions for Galois field arithmetic. We show that by using the instructions, we can speedup Reed-Solomon decoding by a factor of 12 compared to a pure software approach, while still maintaining programmability.