A Dynamic Program Analysis to find Floating-Point Accuracy Problems

作者：Benz Florian^*; Hildebrandt Andreas; Hack Sebastian

来源：ACM Sigplan Notices, 2012, 47(6): 453-462.

DOI：10.1145/2345156.2254118

• Dynamic program analysis
• program instrumentation
• floating-point accuracy

Programs using floating-point arithmetic are prone to accuracy problems caused by rounding and catastrophic cancellation. These phenomena provoke bugs that are notoriously hard to track down: the program does not necessarily crash and the results are not necessarily obviously wrong, but often subtly inaccurate. Further use of these values can lead to catastrophic errors. %26lt;br%26gt;In this paper, we present a dynamic program analysis that supports the programmer in finding accuracy problems. Our analysis uses binary translation to perform every floating-point computation side by side in higher precision. Furthermore, we use a lightweight slicing approach to track the evolution of errors. %26lt;br%26gt;We evaluate our analysis by demonstrating that it catches well-known floating-point accuracy problems and by analyzing the Spec CFP2006 floating-point benchmark. In the latter, we show how our tool tracks down a catastrophic cancellation that causes a complete loss of accuracy leading to a meaningless program result. Finally, we apply our program to a complex, real-world bioinformatics application in which our program detected a serious cancellation. Correcting the instability led not only to improved quality of the result, but also to an improvement of the program%26apos;s run time.

• 出版日期2012-6