Editing Data-flow analysis (section)

== Sensitivities ==
{{main|Polyvariance}}

Data-flow analysis is typically path-insensitive, though it is possible to define data-flow equations that yield a path-sensitive analysis.

* A '''flow-sensitive''' analysis takes into account the order of statements in a program.  For example, a flow-insensitive pointer alias analysis may determine "variables ''x'' and ''y'' may refer to the same location", while a flow-sensitive analysis may determine "after statement 20, variables ''x'' and ''y'' may refer to the same location".
* A '''path-sensitive''' analysis computes different pieces of analysis information dependent on the predicates at conditional branch instructions. For instance, if a branch contains a condition {{code|x>0}}, then on the ''fall-through'' path, the analysis would assume that {{code|1=x<=0}} and on the target of the branch it would assume that indeed {{code|x>0}} holds.
* A '''context-sensitive''' analysis is an ''interprocedural'' analysis that considers the calling context when analyzing the target of a function call. In particular, using context information one can ''jump back'' to the original call site, whereas without that information, the analysis information has to be propagated back to all possible call sites, potentially losing precision.