ECOOP 2018
Sun 15 - Sat 21 July 2018 Amsterdam, Netherlands
co-located with ECOOP and ISSTA 2018
Wed 18 Jul 2018 14:40 - 15:00 at Zurich II - Optimization and Performance Chair(s): Tevfik Bultan

Floating-point types are notorious for their intricate representation. The effective use of mixed precision, i.e., using various precisions in different computations, is critical to achieve a good balance between accuracy and performance. Unfortunately, reasoning about mixed precision is difficult even for numerical experts. Techniques have been proposed to systematically search over floating-point variables and/or program instructions to find a faster, mixed-precision version of a given program. These techniques, however, are characterized by their black box nature, and face scalability limitations due to the large search space. In this paper, we exploit the community structure of floating-point variables to devise a scalable hierarchical search for precision tuning. Specifically, we perform dependence analysis and edge profiling to create a weighted dependence graph that presents a network of floating-point variables. We then formulate hierarchy construction on the network as a community detection problem, and present a hierarchical search algorithm that iteratively lowers precision with regard to communities. We implement our algorithm in the tool HIFPTUNER . Our experimental evaluation shows that HIFPTUNER exhibits higher search efficiency over the state of the art for 75.9% experiments with 59.6% less search time in average. Moreover, HIFPTUNER finds more profitable configurations for 51.7% experiments, with one known to be as good as the global optimal found through exhaustive search.

Wed 18 Jul

Displayed time zone: Amsterdam, Berlin, Bern, Rome, Stockholm, Vienna change

14:00 - 15:30
Optimization and PerformanceISSTA Technical Papers at Zurich II
Chair(s): Tevfik Bultan University of California, Santa Barbara
14:00
20m
Talk
Remove RATs from Your Code: Automated Optimization of Resource Inefficient Database Writes for Mobile Applications
ISSTA Technical Papers
Yingjun Lyu University of Southern California, Ding Li NEC Labs, William G.J. Halfond University of Southern California
14:20
20m
Talk
Badger: Complexity Analysis with Fuzzing and Symbolic Execution
ISSTA Technical Papers
Yannic Noller Humboldt-Universität zu Berlin, Rody Kersten Synopsys, Inc., Corina S. Păsăreanu NASA Ames Research Center
14:40
20m
Talk
Exploiting Community Structure for Floating-Point Precision Tuning
ISSTA Technical Papers
Hui Guo University of California, Davis, Cindy Rubio-González University of California, Davis
15:00
20m
Talk
piCoq: Parallel Regression Proving for Large-Scale Verification Projects
ISSTA Technical Papers
Karl Palmskog University of Texas at Austin, Ahmet Celik University of Texas at Austin, USA, Milos Gligoric University of Texas at Austin
15:20
10m
Q&A in groups
ISSTA Technical Papers