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100
Efficient FlowSensitive Interprocedural Computation of PointerInduced Aliases and Side Effects
, 1993
"... We present practical approximation methods for computing interprocedural aliases and side effects for a program written in a language that includes pointers, reference parameters and recursion. We present the following results: 1) An algorithm for flowsensitive interprocedural alias analysis which ..."
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Cited by 235 (11 self)
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We present practical approximation methods for computing interprocedural aliases and side effects for a program written in a language that includes pointers, reference parameters and recursion. We present the following results: 1) An algorithm for flowsensitive interprocedural alias analysis which is more precise and efficient than the best interprocedural method known. 2) An extension of traditional flowinsensitive alias analysis which accommodates pointers and provides a framework for a family of algorithms which trade off precision for efficiency. 3) An algorithm which correctly computes side effects in the presence of pointers. Pointers cannot be correctly handled by conventional methods for side effect analysis. 4) An alias naming technique which handles dynamically allocated objects and guarantees the correctness of dataflow analysis. 5) A compact representation based on transitive reduction which does not result in a loss of precision and improves precision in some cases. 6)...
Lazy Code Motion
, 1992
"... We present a bitvector algorithm for the optimal and economical placement of computations within flow graphs, which is as efficient as standard unidirectional analyses. The point of our algorithm is the decomposition of the bidirectional structure of the known placement algorithms into a sequenc ..."
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Cited by 170 (20 self)
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We present a bitvector algorithm for the optimal and economical placement of computations within flow graphs, which is as efficient as standard unidirectional analyses. The point of our algorithm is the decomposition of the bidirectional structure of the known placement algorithms into a sequence of a backward and a forward analysis, which directly implies the efficiency result. Moreover, the new compositional structure opens the algorithm for modification: two further unidirectional analysis components exclude any unnecessary code motion. This laziness of our algorithm minimizes the register pressure, which has drastic effects on the runtime behaviour of the optimized programs in practice, where an economical use of registers is essential.
Finding Regular Simple Paths In Graph Databases
, 1989
"... We consider the following problem: given a labelled directed graph G and a regular expression R, find all pairs of nodes connected by a simple path such that the concatenation of the labels along the path satisfies R. The problem is motivated by the observation that many recursive queries in relatio ..."
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Cited by 144 (6 self)
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We consider the following problem: given a labelled directed graph G and a regular expression R, find all pairs of nodes connected by a simple path such that the concatenation of the labels along the path satisfies R. The problem is motivated by the observation that many recursive queries in relational databases can be expressed in this form, and by the implementation of a query language, G+ , based on this observation. We show that the problem is in general intractable, but present an algorithm than runs in polynomial time in the size of the graph when the regular expression and the graph are free of conflicts. We also present a class of languages whose expressions can always be evaluated in time polynomial in the size of both the graph and the expression, and characterize syntactically the expressions for such languages.
Optimal Code Motion: Theory and Practice
, 1993
"... An implementation oriented algorithm for lazy code motion is presented that minimizes the number of computations in programs while suppressing any unnecessary code motion in order to avoid superfluous register pressure. In particular, this variant of the original algorithm for lazy code motion works ..."
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Cited by 115 (18 self)
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An implementation oriented algorithm for lazy code motion is presented that minimizes the number of computations in programs while suppressing any unnecessary code motion in order to avoid superfluous register pressure. In particular, this variant of the original algorithm for lazy code motion works on flowgraphs whose nodes are basic blocks rather than single statements, as this format is standard in optimizing compilers. The theoretical foundations of the modified algorithm are given in the first part, where trefined flowgraphs are introduced for simplifying the treatment of flowgraphs whose nodes are basic blocks. The second part presents the `basic block' algorithm in standard notation, and gives directions for its implementation in standard compiler environments. Keywords Elimination of partial redundancies, code motion, data flow analysis (bitvector, unidirectional, bidirectional), nondeterministic flowgraphs, trefined flow graphs, critical edges, lifetimes of registers, com...
Sharlit  A Tool for Building Optimizers
, 1992
"... This paper presents Sharlit, a tool to support the construction of modular and extensible global optimizers. We will show how Sharlit helps in constructing dataflow analyzers and the transformations that use dataflow analysis information: both are major components of any optimizer. ..."
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Cited by 79 (6 self)
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This paper presents Sharlit, a tool to support the construction of modular and extensible global optimizers. We will show how Sharlit helps in constructing dataflow analyzers and the transformations that use dataflow analysis information: both are major components of any optimizer.
ρQueries: Enabling Querying for Semantic Associations on the Semantic Web
 In Proceedings of the Twelfth International WorldWide Web Conference
, 2003
"... This paper presents the notion of Semantic Associations as complex relationships between resource entities. These relationships capture both a connectivity of entities as well as similarity of entities based on a specific notion of similarity called ρisomorphism. It formalizes these notions for the ..."
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Cited by 70 (16 self)
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This paper presents the notion of Semantic Associations as complex relationships between resource entities. These relationships capture both a connectivity of entities as well as similarity of entities based on a specific notion of similarity called ρisomorphism. It formalizes these notions for the RDF data model, by introducing a notion of a Property Sequence as a type. In the context of a graph model such as that for RDF, Semantic Associations amount to specific certain graph signatures. Specifically, they refer to sequences (i.e. directed paths) here called Property Sequences, between entities, networks of Property Sequences (i.e. undirected paths), or subgraphs of ρisomorphic Property Sequences. The ability to query about the existence of such relationships is fundamental to tasks in analytical domains such as national security and business intelligence, where tasks often focus on finding complex yet meaningful and obscured relationships between entities. However, support for such queries is lacking in contemporary query systems, including those for RDF. This paper discusses how querying for Semantic Associations might be enabled on the Semantic Web, through the use of an operator ρ. It also discusses two approaches for processing ρqueries on available persistent RDF stores and memory resident RDF data graphs, thereby building on current RDF query languages.
COSMOS: A compiled simulator for MOS circuits
 PROCEEDINGS OF THE 24TH DESIGN AUTOMATION CONFERENCE
, 1987
"... The cosmos simulator provides fast and accurate switchlevel modeling of mos digital circuits. It attains high performance by preprocessing the transistor network into a functionally equivalent Boolean representation. This description, produced by the symbolic analyzer anamos, captures all aspects o ..."
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Cited by 65 (0 self)
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The cosmos simulator provides fast and accurate switchlevel modeling of mos digital circuits. It attains high performance by preprocessing the transistor network into a functionally equivalent Boolean representation. This description, produced by the symbolic analyzer anamos, captures all aspects of switchlevel networks including bidirectional transistors, stored charge, different signal strengths, and indeterminate (X) logic values. The lgcc program translates the Boolean representation into a set of machine language evaluation procedures and initialized data structures. These procedures and data structures are compiled along with code implementing the simulation kernel and user interface to produce the simulation program. The simulation program runs an order of magnitude faster than our previous simulator mossim ii.
Elimination algorithms for data flow analysis
 ACM Computing Surveys
, 1986
"... A unified model of a family of data flow algorithms, called elimination methods, is presented. The algorithms, which gather information about the definition and use of data in a program or a set of programs, are characterized by the manner in which they solve the systems of equations that describe d ..."
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Cited by 57 (8 self)
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A unified model of a family of data flow algorithms, called elimination methods, is presented. The algorithms, which gather information about the definition and use of data in a program or a set of programs, are characterized by the manner in which they solve the systems of equations that describe data flow problems of interest. The unified model
A ControlFlow Normalization Algorithm and Its Complexity
 IEEE Transactions on Software Engineering
, 1992
"... We present a simple method for normalizing the controlflow of programs to facilitate program transformations, program analysis, and automatic parallelization. While previous methods result in programs whose control flowgraphs are reducible, programs normalized by this technique satisfy a stronger c ..."
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Cited by 56 (0 self)
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We present a simple method for normalizing the controlflow of programs to facilitate program transformations, program analysis, and automatic parallelization. While previous methods result in programs whose control flowgraphs are reducible, programs normalized by this technique satisfy a stronger condition than reducibility and are therefore simpler in their syntax and structure than with previous methods. In particular, all controlflow cycles are normalized into singleentry, singleexit while loops, and all goto's are eliminated. Furthermore, the method avoids problems of code replication that are characteristic of nodesplitting techniques. This restructuring obviates the control dependence graph, since afterwards control dependence relations are manifest in the syntax tree of the program. In this paper we present transformations that effect this normalization, and study the complexity of the method. Index Terms: Continuations, controlflow, elimination algorithms, normalization,...
Data Flow Frequency Analysis
 In Proc. of the ACM SIGPLAN '96 Conference on Programming Language Design and Implementation (PLDI'96
, 1996
"... Conventional dataflow analysis computes information about what facts may or will not hold during the execution of a program. Sometimes it is useful, for program optimization, to know how often or with what probability a fact holds true during program execution. In this paper, we provide a precise fo ..."
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Cited by 48 (0 self)
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Conventional dataflow analysis computes information about what facts may or will not hold during the execution of a program. Sometimes it is useful, for program optimization, to know how often or with what probability a fact holds true during program execution. In this paper, we provide a precise formulation of this problem for a large class of dataflow problems  the class of finite bidistributive subset problems. We show how it can be reduced to a generalization of the standard dataflow analysis problem, one that requires a sumoverallpaths quantity instead of the usual meetoverall paths quantity. We show that Kildall's result expressing the meetoverallpaths value as a maximalfixedpoint carries over to the generalized setting. We then outline ways to adapt the standard dataflow analysis algorithms to solve this generalized problem, both in the intraprocedural and the interprocedural case. 1 Introduction Conventional dataflow analysis computes information about what facts...