Wed 7 Nov 2018 16:37 - 17:00 at Studio 2 - Compiler Optimization Chair(s): Patrick Lam

Loop-level compiler optimizations are applied in a complex process with no guarantee that the code produced is optimal. Compilers also struggle to maintain a stable performance on different loops with the same semantics. This paper presents an analysis of the stability of the compilation process and shows potential for state-of-the-art compilers to improve code performance. In the study, loop nests are first extracted from benchmarks; then, sequences of source-level loop transformations are applied to these loop nests to create numerous semantically equivalent mutations; finally, the impact of transformations on code quality in terms of locality, dynamic instruction count, and vectorization is analyzed for different compilers. Our results show that up to 47% of the loops can be improved with at least a 1.15x speedup by this process while the average speedup can reach 1.6x for the improved loops. In addition, we propose a novel stability score that demonstrates the difference in stability from the studied compilers. The study concludes that the effect of source-level transformations varies among compilers, and the evaluated compilers have long ways to go until reaching stable.

Wed 7 Nov

15:30 - 17:00: OOPSLA - Compiler Optimization at Studio 2
Chair(s): Patrick LamUniversity of Waterloo
splash-2018-OOPSLA15:30 - 15:52
splash-2018-OOPSLA15:52 - 16:15
Xiaoran XuRice University, Keith CooperRice University, Jacob BrockUniversity of Rochester, Yan Zhang, Handong YeFuturewei Technologies
splash-2018-OOPSLA16:15 - 16:37
Juneyoung LeeSeoul National University, Chung-Kil HurSeoul National University, Ralf JungMPI-SWS, Zhengyang LiuUniversity of Utah, John RegehrUniversity of Utah, Nuno P. LopesMicrosoft Research
splash-2018-OOPSLA16:37 - 17:00
Zhangxiaowen GongUniversity of Illinois at Urbana-Champaign, Zhi ChenUniversity of California, Irvine, Justin SzadayUniversity of Illinois at Urbana-Champaign, David WongIntel, Zehra SuraIBM Research, Neftali Watkinson, Saeed MalekiMicrosoft Research, David PaduaUniversity of Illinois at Urbana-Champaign, Alexander VeidenbaumUniversity of California, Irvine, Alexandru NicolauUniversity of California, Irvine, Josep TorrellasUniversity of Illinois at Urbana-Champaign