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Lazy Satisfiability Modulo Theories

by Roberto Sebastiani - JOURNAL ON SATISFIABILITY, BOOLEAN MODELING AND COMPUTATION 3 (2007) 141€“224 , 2007
"... Satisfiability Modulo Theories (SMT) is the problem of deciding the satisfiability of a first-order formula with respect to some decidable first-order theory T (SMT (T)). These problems are typically not handled adequately by standard automated theorem provers. SMT is being recognized as increasingl ..."
Abstract - Cited by 189 (50 self) - Add to MetaCart
Satisfiability Modulo Theories (SMT) is the problem of deciding the satisfiability of a first-order formula with respect to some decidable first-order theory T (SMT (T)). These problems are typically not handled adequately by standard automated theorem provers. SMT is being recognized as increasingly important due to its applications in many domains in different communities, in particular in formal verification. An amount of papers with novel and very efficient techniques for SMT has been published in the last years, and some very efficient SMT tools are now available. Typical SMT (T) problems require testing the satisfiability of formulas which are Boolean combinations of atomic propositions and atomic expressions in T, so that heavy Boolean reasoning must be efficiently combined with expressive theory-specific reasoning. The dominating approach to SMT (T), called lazy approach, is based on the integration of a SAT solver and of a decision procedure able to handle sets of atomic constraints in T (T-solver), handling respectively the Boolean and the theory-specific components of reasoning. Unfortunately, neither the problem of building an efficient SMT solver, nor even that
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Translating pseudo-boolean constraints into SAT

by Niklas Eén, Niklas Sörensson - Journal on Satisfiability, Boolean Modeling and Computation , 2006
"... In this paper, we describe and evaluate three different techniques for translating pseudoboolean constraints (linear constraints over boolean variables) into clauses that can be handled by a standard SAT-solver. We show that by applying a proper mix of translation techniques, a SAT-solver can perfor ..."
Abstract - Cited by 184 (2 self) - Add to MetaCart
In this paper, we describe and evaluate three different techniques for translating pseudoboolean constraints (linear constraints over boolean variables) into clauses that can be handled by a standard SAT-solver. We show that by applying a proper mix of translation techniques, a SAT-solver can perform on a par with the best existing native pseudo-boolean solvers. This is particularly valuable in those cases where the constraint problem of interest is naturally expressed as a SAT problem, except for a handful of constraints. Translating those constraints to get a pure clausal problem will take full advantage of the latest improvements in SAT research. A particularly interesting result of this work is the efficiency of sorting networks to express pseudo-boolean constraints. Although tangential to this presentation, the result gives a suggestion as to how synthesis tools may be modified to produce arithmetic circuits more suitable for SAT based reasoning. Keywords: pseudo-Boolean, SAT-solver, SAT translation, integer linear programming
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Test Input Generation with Java PathFinder

by Willem Visser, Corina S. Pasareanu, Sarfraz Khurshid
"... We show how model checking and symbolic execution can be used to generate test inputs to achieve structural coverage of code that manipulates complex data structures. We focus on obtaining branch-coverage during unit testing of some of the core methods of the red-black tree implementation in the Jav ..."
Abstract - Cited by 184 (7 self) - Add to MetaCart
We show how model checking and symbolic execution can be used to generate test inputs to achieve structural coverage of code that manipulates complex data structures. We focus on obtaining branch-coverage during unit testing of some of the core methods of the red-black tree implementation in the Java TreeMap library, using the Java PathFinder model checker. Three di#erent test generation techniques will be introduced and compared, namely, straight model checking of the code, model checking used in a black-box fashion to generate all inputs up to a fixed size, and lastly, model checking used during white-box test input generation. The main contribution of this work is to show how e#cient white-box test input generation can be done for code manipulating complex data, taking into account complex method preconditions.

Cache Miss Equations: A Compiler Framework for Analyzing and Tuning Memory Behavior

by Somnath Ghosh, Margaret Martonosi, Sharad Malik - ACM Transactions on Programming Languages and Systems , 1999
"... This article describes methods for generating and solving Cache Miss Equations (CMEs) that give a detailed representation of cache behavior, including conflict misses, in loop-oriented scientific code. Implemented within the SUIF compiler framework, our approach extends traditional compiler reuse an ..."
Abstract - Cited by 168 (1 self) - Add to MetaCart
This article describes methods for generating and solving Cache Miss Equations (CMEs) that give a detailed representation of cache behavior, including conflict misses, in loop-oriented scientific code. Implemented within the SUIF compiler framework, our approach extends traditional compiler reuse analysis to generate linear Diophantine equations that summarize each loop's memory behavior. While solving these equations is in general di#- cult, we show that is also unnecessary, as mathematical techniques for manipulating Diophantine equations allow us to relatively easily compute and/or reduce the number of possible solutions, where each solution corresponds to a potential cache miss. The mathematical precision of CMEs allows us to find true optimal solutions for transformations such as blocking or padding. The generality of CMEs also allows us to reason about interactions between transformations applied in concert. The article also gives examples of their use to determine array padding and o#set amounts that minimize cache misses, and to determine optimal blocking factors for tiled code. Overall, these equations represent an analysis framework that o#ers the generality and precision needed for detailed compiler optimizations
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Proving the correctness of reactive systems using sized types

by John Hughes, Lars Pareto, Amr Sabry , 1996
"... { rjmh, pareto, sabry We have designed and implemented a type-based analysis for proving some baaic properties of reactive systems. The analysis manipulates rich type expressions that contain in-formation about the sizes of recursively defined data struc-tures. Sized types are useful for detecting d ..."
Abstract - Cited by 151 (3 self) - Add to MetaCart
{ rjmh, pareto, sabry We have designed and implemented a type-based analysis for proving some baaic properties of reactive systems. The analysis manipulates rich type expressions that contain in-formation about the sizes of recursively defined data struc-tures. Sized types are useful for detecting deadlocks, non-termination, and other errors in embedded programs. To establish the soundness of the analysis we have developed an appropriate semantic model of sized types. 1 Embedded Functional Programs In a reactive system, the control software must continu-ously react to inputs from the environment. We distin-guish a class of systems where the embedded programs can be naturally expressed as functional programs manipulat-ing streams. This class of programs appears to be large enough for many purposes [2] and is the core of more ex-pressive formalisms that accommodate asynchronous events, non-determinism, etc. The fundamental criterion for the correctness of pro-grams embedded in reactive systems is Jwene.ss. Indeed, before considering the properties of the output, we must en-sure that there is some output in the first place: the program must continuous] y react to the input streams by producing elements on the output streams. This latter property may fail in various ways: e the computation of a stream element may depend on itself creating a “black hole, ” or e the computation of one of the output streams may demand elements from some input stream at different rates, which requires unbounded buffering, or o the computation of a stream element may exhaust the physical resources of the machine or even diverge.
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Analyzing Memory Accesses in x86 Executables

by Gogul Balakrishnan, Thomas Reps - In CC , 2004
"... This paper concerns static-analysis algorithms for analyzing x86 executables. ..."
Abstract - Cited by 147 (28 self) - Add to MetaCart
This paper concerns static-analysis algorithms for analyzing x86 executables.
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Symbolic Bounds Analysis of Pointers, Array Indices, and Accessed Memory Regions

by Radu Rugina, Martin Rinard - PLDI 2000 , 2000
"... This paper presents a novel framework for the symbolic bounds analysis of pointers, array indices, and accessed memory regions. Our framework formulates each analysis problem as a system of inequality constraints between symbolic bound polynomials. It then reduces the constraint system to a linear p ..."
Abstract - Cited by 134 (15 self) - Add to MetaCart
This paper presents a novel framework for the symbolic bounds analysis of pointers, array indices, and accessed memory regions. Our framework formulates each analysis problem as a system of inequality constraints between symbolic bound polynomials. It then reduces the constraint system to a linear program. The solution to the linear program provides symbolic lower and upper bounds for the values of pointer and array index variables and for the regions of memory that each statement and procedure accesses. This approach eliminates fundamental problems associated with applying standard xed-point approaches to symbolic analysis problems. Experimental results from our implemented compiler show that the analysis can solve several important problems, including static race detection, automatic parallelization, static detection of array bounds violations, elimination of array bounds checks, and reduction of the number of bits used to store computed values.

Automatic Program Parallelization

by Utpal Banerjee, Rudolf Eigenmann, Alexandru Nicolau, David A. Padua , 1993
"... This paper presents an overview of automatic program parallelization techniques. It covers dependence analysis techniques, followed by a discussion of program transformations, including straight-line code parallelization, do loop transformations, and parallelization of recursive routines. The last s ..."
Abstract - Cited by 124 (8 self) - Add to MetaCart
This paper presents an overview of automatic program parallelization techniques. It covers dependence analysis techniques, followed by a discussion of program transformations, including straight-line code parallelization, do loop transformations, and parallelization of recursive routines. The last section of the paper surveys several experimental studies on the effectiveness of parallelizing compilers.

A practical automatic polyhedral parallelizer and locality optimizer

by Uday Bondhugula, Albert Hartono, J. Ramanujam - In PLDI ’08: Proceedings of the ACM SIGPLAN 2008 conference on Programming language design and implementation , 2008
"... We present the design and implementation of an automatic polyhedral source-to-source transformation framework that can optimize regular programs (sequences of possibly imperfectly nested loops) for parallelism and locality simultaneously. Through this work, we show the practicality of analytical mod ..."
Abstract - Cited by 122 (8 self) - Add to MetaCart
We present the design and implementation of an automatic polyhedral source-to-source transformation framework that can optimize regular programs (sequences of possibly imperfectly nested loops) for parallelism and locality simultaneously. Through this work, we show the practicality of analytical model-driven automatic transformation in the polyhedral model.Unlike previous polyhedral frameworks, our approach is an end-to-end fully automatic one driven by an integer linear optimization framework that takes an explicit view of finding good ways of tiling for parallelism and locality using affine transformations. The framework has been implemented into a tool to automatically generate OpenMP parallel code from C program sections. Experimental results from the tool show very high performance for local and parallel execution on multi-cores, when compared with state-of-the-art compiler frameworks from the research community as well as the best native production compilers. The system also enables the easy use of powerful empirical/iterative optimization for general arbitrarily nested loop sequences.
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Cache Miss Equations: An Analytical Representation of Cache Misses

by Somnath Ghosh, Margaret Martonosi, Sharad Malik - In Proceedings of the 1997 ACM International Conference on Supercomputing , 1997
"... With the widening performance gap between processors and main memory, efficient memory accessing behavior is necessary for good program performance. Both hand-tuning and compiler optimization techniques are often used to transform codes to improve memory performance. Effective transformations requir ..."
Abstract - Cited by 115 (4 self) - Add to MetaCart
With the widening performance gap between processors and main memory, efficient memory accessing behavior is necessary for good program performance. Both hand-tuning and compiler optimization techniques are often used to transform codes to improve memory performance. Effective transformations require detailed knowledge about the frequency and causes of cache misses in the code.