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

Displayed time zone: Guadalajara, Mexico City, Monterrey change

15:30 - 17:00
Compiler OptimizationOOPSLA at Studio 2
Chair(s): Patrick Lam University of Waterloo
15:30
22m
Talk
Format Abstraction for Sparse Tensor Algebra Compilers
OOPSLA
15:52
22m
Talk
ShareJIT: JIT Code Cache Sharing across Processes and its Practical Implementation
OOPSLA
Xiaoran Xu Rice University, Keith Cooper Rice University, Jacob Brock University of Rochester, Yan Zhang , Handong Ye Futurewei Technologies
16:15
22m
Talk
Reconciling High-level Optimizations and Low-level Code in LLVM
OOPSLA
Juneyoung Lee Seoul National University, Chung-Kil Hur Seoul National University, Ralf Jung MPI-SWS, Zhengyang Liu University of Utah, John Regehr University of Utah, Nuno P. Lopes Microsoft Research
Pre-print
16:37
22m
Talk
An Empirical Study of the Effect of Source-level Loop Transformations on Compiler Stability
OOPSLA
Zhangxiaowen Gong University of Illinois at Urbana-Champaign, Zhi Chen University of California, Irvine, Justin Szaday University of Illinois at Urbana-Champaign, David Wong Intel, Zehra Sura IBM Research, Neftali Watkinson , Saeed Maleki Microsoft Research, David Padua University of Illinois at Urbana-Champaign, Alexander Veidenbaum University of California, Irvine, Alexandru Nicolau University of California, Irvine, Josep Torrellas University of Illinois at Urbana-Champaign
Media Attached