Pointer aliasing analysis is used to determine if two object names containing dereferences and/or field selectors, (e.g., *p,q->t), may refer to the same location during execution.Such information is necessary for applications such as dataflow-based testers, program understanding tools, and debuggers, but is expensive to calculate with acceptable precision.Incremental algorithms update data flow information after a program change rather than recomputing it from scratch, under the assumption that the change impact will be limited.Two versions of a practical incremental pointer aliaaing algorithm have been developed, based on Land&Ryder flow-and context-sensitive alias analysis.Empirical results attest to the time savings over exhaustive analysis (a six-fold speedup on average), and the precision of the approximate solution obtained (on average same solution as exhaustive algorithm for 75% of the tests.)

Incremental static analysis seeks to efficiently update semantic information about an evolving software system, without recomputing “from scratch.” Interprocedural modification side effect analysis (MOD) calculates the set of variables possibly modified by execution of a procedure or a statement. We introduce a partial incrementalization of MOD for C systems using the hybrid method and present results of a study of 27 C programs, that predicts that our incremental MOD analysis will be substantially cheaper than exhaustive analysis for many program changes.

The problem of finding an optimal assignment of task modules with a precedence relationship in a distributed computing system is considered. The objective of task assignment is to minimize the task turnaround time. The problem is known to be NP-complete for more than three processors. To solve the problem, a well-known state-space reduction technique, branch-and-bound-with-underestimates, is applied, and two underestimate functions are defined. Through experiments, their effectiveness is shown by comparing the proposed algorithm with both Wang and Tsai's (1988) algorithm and the A* algorithm with h(x)=0.>