... This paper concerns the problem of interprocedural slicing---generating a slice of an entire program, where the slice crosses the boundaries of procedure calls. To solve this problem, we introduce a new kind of graph to represent programs, called a system dependence graph, which extends previous dependence representations to incorporate collections of procedures (with procedure calls) rather than just monolithic programs. Our main result is an algorithm for interprocedural slicing that uses the new representation. (It should be noted that our work concerns a somewhat restricted kind of slice: Rather than permitting a program to be sliced with respect to program point p and an arbitrary variable, a slice must be taken with respect to a variable that is defined or used at p.) The chief

This paper describes how a number of program-analysis problems can be solved by transforming them to graph-reachability problems. Some of the program-analysis problems that are amenable to this treatment include program slicing, certain dataflow-analysis problems, and the problem of approximating the possible "shapes" that heap-allocated structures in a program can take on. Relationships between graph reachability and other approaches to program analysis are described. Some techniques that go beyond pure graph reachability are also discussed.

This paper presents a general framework for deriving demanddriven algorithms for interprocedural data flow analysis of imperative programs. The goal of demand-driven analysis is to reduce the time and/or space overhead of conventional exhaustive analysis by avoiding the collection of information that is not needed. In our framework, a demand for data flow information is modeled as a set of data flow queries. The derived demand-driven algorithms find responses to these queries through a partial reversal of the respective data flow analysis. Depending on whether minimizing time or space is of primary concern, result caching may be incorporated in the derived algorithm. Our framework is applicable to interprocedural data flow problems with a finite domain set. If the problem's flow functions are distributive, the derived demand algorithms provide as precise information as the corresponding exhaustive analysis. For problems with monotone but non-distributive flow functions the provided dat...

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Data flow analysis is the prerequisite of performing optimizations such as code motion of partial redundant expressions on imperative sequential programs. To apply these transformations to parallel imperative programs, the notion of data flow must be extended to concurrent programs. The additional parallel source language features are: shared memory and nested parallel statements (PAR). The underlying interleaving semantics of the concurrently-executed processes result in the so-called state space explosion which on first appearance prevents the computation of the meet over all path solution needed for data flow analysis. For the class of bit-vector data flow problems we can show that for the computation of the meet over all path solution, not all interleavings are needed. Based on that, we can give simple data flow equations representing the data flow effects of the PAR statement. The definition of a parallel control flow graph leads to an efficient extension of Killdal 's algorithm ...

Attribute grammars (AGs) are a suitable formalism for development of language processing systems. However, for languages including unrestricted labeled jumps, like "goto" in C, optimizers in compilers are hard to write in AGs. This is due to two problems which few previous researches could deal with simultaneously, i.e., references of attribute values on distant nodes and circularity in attribute dependency. This paper proposes circular remote attribute grammars (CRAGs), an extension of AGs which allows (1) direct relations between two distant attribute instances through pointers referring to other nodes in the derivation tree, and (2) circular dependencies under certain conditions including those which arise from remote references. This extension gives AG programmers a natural way to describe language processors and programming environments for languages including any type of jump structures. We will also show a way to construct an e#cient evaluator for CRAGs called a mostly static evaluator. Performance of the proposed evaluator has been measured and compared with dynamic and static evaluators.

Building verified compilers is difficult, especially when complex analyses such as type checking or data-flow analysis must be performed. Both the type checking and program optimization communities have developed methods for proving the correctness of these processes and developed tools for using, respectively, verified type systems and verified optimizations. However, it is difficult to use both of these analyses in a single declarative framework since these processes work on different program representations: type checking on abstract syntax trees and data-flow analysis-based optimization on control flow or program dependency graphs. We present an attribute grammar specification language that has been extended with constructs for specifying attribute-labelled control flow graphs and both CTL and LTL-FV formulas that specify data-flow analyses. These formulas are modelchecked on these graphs to perform the specified analyses. Thus, verified type rules and verified data-flow analyses (verified either by hand or with automated proof tools) can both be transcribed into a single declarative framework based on attribute grammars to build a high-confidence language implementations. Also, the attribute grammar specification language is extensible so that it is relatively straight-forward to add new constructs for different temporal logics so that alternative logics and model checkers can be used to specify data-flow analyses in this framework. Key words: compiler optimization, optimization verification, data flow analysis, attribute grammars 1

this paper, we present a new approach to studying program-integration algorithms. In particular, we introduce