Software engineers are faced with a dilemma. They want to write general and wellstructured programs that are flexible and easy to maintain. On the other hand, generality has a price: efficiency. A specialized program solving a particular problem is often significantly faster than a general program. However, the development of specialized software is time-consuming, and is likely to exceed the production of today’s programmers. New techniques are required to solve this so-called software crisis. Partial evaluation is a program specialization technique that reconciles the benefits of generality with efficiency. This thesis presents an automatic partial evaluator for the Ansi C programming language. The content of this thesis is analysis and transformation of C programs. We develop several analyses that support the transformation of a program into its generating extension. A generating extension is a program that produces specialized programs when executed on parts of the input. The thesis contains the following main results.

Relevant context inference (RCI) is a modular technique for flow- and context-sensitive data-flow analysis of statically typed object-oriented programming languages such as C ++ and Java. RCI can be used to analyze complete programs as well as incomplete programs such as libraries; this approach does not require that the entire program be memoryresident during the analysis. RCI is presented in the context of points-to analysis for a realistic subset of C ++ . The empirical evidence obtained from a prototype implementation argues the effectiveness of RCI. 1 Introduction Points-to analysis [EGH94] for statically typed objectoriented programming languages (e.g., Java, C ++ ) determines, at each program point, the objects to which a pointer may point during execution. This information is crucial to many applications, including static resolution of dynamically dispatched calls, side-effect analysis, data-flow-based testing, program slicing and aggressive compiler optimizations. The s...

This article presents a testing methodology that adapts data flow adequacy criteria and coverage monitoring to the task of testing spreadsheets. To accommodate the evaluation model used with spreadsheets, and the interactive process by which they are created, our methodology is incremental. To accommodate the users of spreadsheet languages, we provide an interface to our methodology that does not require an understanding of testing theory. We have implemented our testing methodology in the context of the Forms/3 visual spreadsheet language. We report on the methodology, its time and space costs, and the mapping from the testing strategy to the user interface. In an empirical study, we found that test suites created according to our methodology detected, on average, 81% of the faults in a set of faulty spreadsheets, significantly outperforming randomly generated test suites

Abstract not found

. Data-flow analysis algorithms can be classified into two categories: flow-sensitive and flow-insensitive. To improve efficiency, flowinsensitive interprocedural analyses do not make use of the intraprocedural control flow information associated with individual procedures. Since pointer-induced aliases can change within a procedure, applying known flow-insensitive analyses can result in either incorrect or overly conservative solutions. In this paper, we present a flow-insensitive dataflow analysis algorithm that computes interprocedural pointer-induced aliases. We improve the precision of our analysis by (1) making use of certain types of kill information that can be precomputed efficiently, and (2) computing aliases generated in each procedure instead of holding at the exit of each procedure. We improve the efficiency of our algorithm by introducing a technique called deferred evaluation. Interprocedural analyses, including alias analysis, rely upon the program call graph (PCG) fo...

This dissertation addresses a number of important issues related to interprocedural optimization. Interprocedural optimization is an integral component in a compilation system for high-performance computing. The importance of interprocedural optimization stems from two sources: it increases the context available to the optimizing compiler, and it enables programmers to use procedure calls without the concern of hurting execution time. While important, interprocedural optimization can introduce some significant compile-time costs. When interprocedural information is used to optimize a procedure, the procedure is then dependent on those interprocedural facts. Thus, even if the procedure is not edited, it may require recompilation due to changes in the interprocedural facts. In addition to these effects on recompilation, interprocedural information can also be expensive to compute. Furthermore, interprocedural optimizations can increase program size which can in turn increase compile tim...

An Alias occurs at some program point during execution when two or more names exist for the same location. We've investigated the theoretical difficulty of determining the aliases of a program, developed an approximation algorithm for solving for aliases in C like languages, and explored the precision (i.e., closeness of our approximate solution to the actual solution) and time behavior of this algorithm. Myers [Mye81] explored the theoretical difficulty of solving flow sensitive interprocedural data flow problems in the presence of aliasing. However, he did not make any claims about the difficulty of determining aliases. We isolate various programming language mechanisms that create aliases. The complexity of the alias problem (i.e., determining the aliases for a program) induced by each mechanism and their combinations is considered s...

In this paper, we describe the program structure tree (PST), a hierarchical representation of program structure based on single entry single exit (SESE) regions of the control flow graph. We give a linear-time algorithm for finding SESE regions and for building the PST of arbitrary control flow graphs (including irreducible ones). Next, we establish a connection between SESE regions and control dependence equivalence classes, and show how to use the algorithm to find control regions in linear time. Finally, we discuss some applications of the PST. Many control-flow algorithms, such as construction of Static Single Assignment form, can be speeded up by applying the algorithms in a divide-and-conquer style to each SESE region on its own. The PST is also used to speed up data flow analysis by exploiting `sparsity'. Experimental results from the Perfect Club and SPEC89 benchmarks confirm that the PST approach finds and exploits program structure.

this article, we present a general framework for developing demand-driven interprocedural data flow analyzers and report our experience in evaluating the performance of this approach. A demand for data flow information is modeled as a set of queries. The framework includes a generic demand-driven algorithm that determines the response to a query by iteratively applying a system of query propagation rules. The propagation rules yield precise responses for the class of distributive finite data flow problems. We also describe a two-phase framework variation to accurately handle nondistributive problems. A performance evaluation of our demand-driven approach is presented for two data flow problems, namely, reaching-definitions and copy constant propagation. Our experiments show that demand-driven analysis performs well in practice, reducing both time and space requirements when compared with exhaustive analysis.

Form-based visual programming languages, which include commercial spreadsheets and various research systems, have had a substantial impact on end-user computing. Research shows, however, that form-based visual programs often contain faults. We would like to provide at least some of the benefits of formal testing methodologies to the creators of these programs. This paper presents a testing methodology for form-based visual programs. To accommodate the evaluation model used with these programs, and the interactive process by which they are created, our methodology is validationdriven and incremental. To accommodate the users of these languages, we provide an interface to the methodology that does not require an understanding of testing theory. We discuss our implementation of this methodology and empirical results achieved in its use.