POPL 2017
Sun 15 - Sat 21 January 2017
Wed 18 Jan 2017 17:20 - 17:45 at Auditorium - Compiler Optimisation Chair(s): Andrew C. Myers

Virtually all real-valued computations are carried out using floating-point data types and operations. The precision of these data types must be set with the goals of reducing the overall round-off error, but also emphasizing reduced data movement and cache occupancy costs. Often, a mixed precision allocation achieves this optimum; unfortunately, there are no techniques available to compute such allocations and conservatively meet a given error target across all program inputs. In this work, we present a rigorous approach to precision allocation based on formal analysis via Symbolic Taylor Expansions, and error analysis based on interval functions. This approach is implemented in an automated tool called FPTUNER that generates and solves a quadratically constrained quadratic program to obtain a precision-annotated version of the given expression. FPTUNER automatically introduces all the requisite precision up/down casting operations. It also allows users to flexibly control precision allocation through constraints, including capping the number of high precision operators, grouping a collection of operators to allocate the same precision for them (to facilitate vectorization), etc. Our evaluation, including real energy measurements on an ARM (Jetson) hardware platform, demonstrate the degree to which precision choices can be exercised, especially controlling compiler optimizations, and the energy impacts of these allocations.

Wed 18 Jan

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

16:30 - 17:45
Compiler OptimisationPOPL at Auditorium
Chair(s): Andrew C. Myers Cornell University
16:30
25m
Talk
A Program Optimization for Automatic Database Result Caching
POPL
Ziv Scully Carnegie Mellon University, Adam Chlipala MIT
16:55
25m
Talk
Stream Fusion, to Completeness
POPL
Oleg Kiselyov , Aggelos Biboudis University of Athens, Nick Palladinos Nessos Information Technologies, SA, Yannis Smaragdakis University of Athens
Pre-print Media Attached
17:20
25m
Talk
Rigorous Floating-point Mixed Precision Tuning
POPL
Wei-Fan Chiang School of Computing, University of Utah, Ganesh Gopalakrishnan University of Utah, Zvonimir Rakamaric University of Utah, Ian Briggs School of Computing, University of Utah, Marek S. Baranowski University of Utah, Alexey Solovyev School of Computing, University of Utah
Pre-print