(CF '19 - PROCEEDINGS OF THE 16TH ACM INTERNATIONAL CONFERENCE ON COMPUTING FRONTIERS, 2019-04-30) Rodriguez-Cancio, Marcelino; Combemale, Benoit; Baudry, Benoit
We introduce Approximate Unrolling, a compiler loop optimization that reduces execution time and energy consumption, exploiting code regions that can endure some approximation and still produce acceptable results. Specifically, this work focuses on counted loops that map a function over the elements of an array. Approximate Unrolling transforms loops similarly to Loop Unrolling. However, unlike its exact counterpart, our optimization does not unroll loops by adding exact copies of the loop's body. Instead, it adds code that interpolates the results of previous iterations.