An improved bound for call strings based interprocedural analysis of bit vector frameworks

Abstract

Interprocedural data flow analysis extends the scope of analysis across procedure boundaries in search of increased optimization opportunities. Call strings based approach is a general approach for performing flow and context sensitive interprocedural analysis. It maintains a history of calls along with the data flow information in the form of call strings, which are sequences of unfinished calls. Recursive programs may need infinite call strings for interprocedural data flow analysis. For bit vector frameworks this method is believed to require all call strings of lengths up to 3K , where K is the maximum number of distinct call sites in any call chain.We combine the nature of information flows in bit-vector data flow analysis with the structure of interprocedurally valid paths to bound the call strings. Instead of bounding the length of call strings, we bound the number of occurrences of any call site in a call string. We show that the call strings in which a call site appears at most three times, are sufficient for convergence on interprocedural maximum fixed point solution. Though this results in the same worst case length of call strings, it does not require constructing all call strings up to length 3K . Our empirical measurements on recursive programs show that our bound reduces the lengths and the number of call strings, and hence the analysis time, significantly.

Contribution-based call stack abstraction for call string based pointer analysis

“…In other work on call string based static analysis, Karkare and Khedker [32] propose an approach that bounds the number of occurrences of any call site in a call string instead of bounding the string length. Their empirical results show that this is enough for achieving high precision and can significantly reduce the analysis time.…”

“…Their empirical results show that this is enough for achieving high precision and can significantly reduce the analysis time. Besides [32], Khedker and Karkare [33] also modify the classical call string method by identifying contexts which need not be explicitly maintained. This reduces the number of calling contexts dramatically without compromising on the precision, generality and simplicity of the method.…”

Large Spurious Cycle in Global Static Analyses and Its Algorithmic Mitigation

“…Full call-strings approaches [17,9,10] and functional approaches [17] do not suffer from spurious cycles but are limited to restricted classes of data flow analysis problems. The original full call-strings method [17] prescribes the domain to be finite and its improved algorithms [9,10] are also limited to bit-vector problems or finite domains.…”

“…The original full call-strings method [17] prescribes the domain to be finite and its improved algorithms [9,10] are also limited to bit-vector problems or finite domains. Khedker et al's algorithm [10] supports infinite domains only for demand-driven analysis.…”

Efficiency, Precision, Simplicity, and Generality in Interprocedural Data Flow Analysis: Resurrecting the Classical Call Strings Method

“…The occurrence based bound for call strings for bit-vector frameworks [12] is an improvement over the classical length bound [22]. It constructs call strings with any call site occurring at most 3 times instead of all call strings with lengths up to 3K.…”