One of the important issues in constructing interprocedural program slices is maintaining context-sensitivity or preserving calling context when a procedure is called at multiple call sites. Though a number of context-sensitive techniques have been presented in the last decade, the following important questions remain unanswered: 1) What is the level of precision lost if context-sensitivity is not maintained ? 2) What are the additional costs for achieving context-sensitivity? In this paper, we evaluate a PDG based explicitly context-sensitive interprocedural program slicing technique for accuracy and efficiency. We compare this technique against a context-insensitive technique using a program slicing frame-work we have developed for Java programs for which only the byte-code sequences are available. Our results show that the context-sensitive technique, in spite of its worst case exponential complexity, can be very efficient in practice. The execution time for our set of bench-marks is, on the average, only twice as much as the execution time for the context-insensitive technique. The results on the accuracy for the context-insensitive technique are mixed. For 53% of the 2464 slicing criteria used in our experiments, the context-insensitive technique does not loose accuracy. However, in some cases, it can also lead to slices with 35 times more vertices. On the average, the slices constructed from the context-insensitive technique are twice as large as the one from the context-sensitive technique.
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