An algorithmic mitigation of large spurious interprocedural cycles in static analysis

In the approximate call-strings-based context-sensitive static analysis, because the number of distinguished contexts is finite, multiple call-contexts are inevitably joined at the entry of a procedure and the output at the exit is propagated to multiple returnsites. We found that these multiple returns frequently create a single large cycle (we call it “butterfly cycle”) covering almost all parts of the program and such a spurious cycle makes analyses very slow and inaccurate.