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18
Symbolic Analysis for Parallelizing Compilers
, 1994
"... Symbolic Domain The objects in our abstract symbolic domain are canonical symbolic expressions. A canonical symbolic expression is a lexicographically ordered sequence of symbolic terms. Each symbolic term is in turn a pair of an integer coefficient and a sequence of pairs of pointers to program va ..."
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Cited by 105 (4 self)
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Symbolic Domain The objects in our abstract symbolic domain are canonical symbolic expressions. A canonical symbolic expression is a lexicographically ordered sequence of symbolic terms. Each symbolic term is in turn a pair of an integer coefficient and a sequence of pairs of pointers to program variables in the program symbol table and their exponents. The latter sequence is also lexicographically ordered. For example, the abstract value of the symbolic expression 2ij+3jk in an environment that i is bound to (1; (( " i ; 1))), j is bound to (1; (( " j ; 1))), and k is bound to (1; (( " k ; 1))) is ((2; (( " i ; 1); ( " j ; 1))); (3; (( " j ; 1); ( " k ; 1)))). In our framework, environment is the abstract analogous of state concept; an environment is a function from program variables to abstract symbolic values. Each environment e associates a canonical symbolic value e x for each variable x 2 V ; it is said that x is bound to e x. An environment might be represented by...
Program improvement by sourcetosource transformation
 J. ACM
, 1977
"... ABSTRACT The use of sourcetosource program transformations has proved valuable in improving program performance The concept of program mampulatlon is elucidated by describing its role in both conventional optnmJzatmn and high level modification of condltnonal, looping, and procedure structures An ..."
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Cited by 51 (0 self)
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ABSTRACT The use of sourcetosource program transformations has proved valuable in improving program performance The concept of program mampulatlon is elucidated by describing its role in both conventional optnmJzatmn and high level modification of condltnonal, looping, and procedure structures An example program fragment written in an Algollike language is greatly improved by transformations enabled by a userprovided assertion about a data array A compllatnon model based on the use of sourcetosource program transformations is used to provide a framework for discussing nssues of code generatnon, compllatnon of high level languages such as APL, and ehmlnatmg overhead commonly associated with modular structured programming Application of the compilation model to several different languages is discussed
A Survey and Classification of some Program Transformation Approaches and Techniques
 In TC2 IFIP Working Conference on Program Specification and Transformation
, 1987
"... Program transformation is a means to formally develop efficient programs from lucid specifications. A representative sample of the diverse range of program transformation research is classified into several different approaches based upon the motivations for and styles of constructing such formal de ..."
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Cited by 44 (0 self)
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Program transformation is a means to formally develop efficient programs from lucid specifications. A representative sample of the diverse range of program transformation research is classified into several different approaches based upon the motivations for and styles of constructing such formal developments. Individual techniques for supporting construction of developments are also surveyed, and are related to the various approaches.
Deriving incremental programs
, 1993
"... A systematic approach i s g i v en for deriving incremental programs from nonincremental programs written in a standard functional programming language. We exploit a number of program analysis and transformation techniques and domainspeci c knowledge, centered around e ective utilization of cachin ..."
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Cited by 39 (21 self)
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A systematic approach i s g i v en for deriving incremental programs from nonincremental programs written in a standard functional programming language. We exploit a number of program analysis and transformation techniques and domainspeci c knowledge, centered around e ective utilization of caching, in order to provide a degree of incrementality not otherwise achievable by a generic incremental evaluator. 1
Automatic Accurate TimeBound Analysis for HighLevel Languages
 In Proceedings of the ACM SIGPLAN 1998 Workshop on Languages, Compilers, and Tools for Embedded Systems, volume 1474 of Lecture Notes in Computer Science
, 1998
"... This paper describes a general approach for automatic and accurate timebound analysis. The approach consists of transformations for building timebound functions in the presence of partially known input structures, symbolic evaluation of the timebound function based on input parameters, optimizati ..."
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Cited by 38 (9 self)
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This paper describes a general approach for automatic and accurate timebound analysis. The approach consists of transformations for building timebound functions in the presence of partially known input structures, symbolic evaluation of the timebound function based on input parameters, optimizations to make the overall analysis efficient as well as accurate, and measurements of primitive parameters, all at the sourcelanguage level. We have implemented this approach and performed a number of experiments for analyzing Scheme programs. The measured worstcase times are closely bounded by the calculated bounds. 1 Introduction Analysis of program running time is important for realtime systems, interactive environments, compiler optimizations, performance evaluation, and many other computer applications. It has been extensively studied in many fields of computer science: algorithms [20, 12, 13, 41], programming languages [38, 21, 30, 33], and systems [35, 28, 32, 31]. It is particularl...
Dynamic programming via static incrementalization
 In Proceedings of the 8th European Symposium on Programming
, 1999
"... Dynamic programming is an important algorithm design technique. It is used for solving problems whose solutions involve recursively solving subproblems that share subsubproblems. While a straightforward recursive program solves common subsubproblems repeatedly and often takes exponential time, a dyn ..."
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Cited by 26 (12 self)
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Dynamic programming is an important algorithm design technique. It is used for solving problems whose solutions involve recursively solving subproblems that share subsubproblems. While a straightforward recursive program solves common subsubproblems repeatedly and often takes exponential time, a dynamic programming algorithm solves every subsubproblem just once, saves the result, reuses it when the subsubproblem is encountered again, and takes polynomial time. This paper describes a systematic method for transforming programs written as straightforward recursions into programs that use dynamic programming. The method extends the original program to cache all possibly computed values, incrementalizes the extended program with respect to an input increment to use and maintain all cached results, prunes out cached results that are not used in the incremental computation, and uses the resulting incremental program to form an optimized new program. Incrementalization statically exploits semantics of both control structures and data structures and maintains as invariants equalities characterizing cached results. The principle underlying incrementalization is general for achieving drastic program speedups. Compared with previous methods that perform memoization or tabulation, the method based on incrementalization is more powerful and systematic. It has been implemented and applied to numerous problems and succeeded on all of them. 1
Automatic Accurate CostBound Analysis for HighLevel Languages
, 2001
"... This paper describes a languagebased approach for automatic and accurate costbound analysis. The approach consists of transformations for building costbound functions in the presence of partially known input structures, symbolic evaluation of the costbound function based on input size parameter ..."
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Cited by 15 (4 self)
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This paper describes a languagebased approach for automatic and accurate costbound analysis. The approach consists of transformations for building costbound functions in the presence of partially known input structures, symbolic evaluation of the costbound function based on input size parameters, and optimizations to make the overall analysis ecient as well as accurate, all at the sourcelanguage level. The calculated cost bounds are expressed in terms of primitive cost parameters. These parameters can be obtained based on the language implementation or be measured conservatively or approximately, yielding accurate, conservative, or approximate time or space bounds. We have implemented this approach and performed a number of experiments for analyzing Scheme programs. The results helped conrm the accuracy of the analysis.
HigherOrder Expression Procedures
 In Proceedings of the ACM SIGPLAN Symposium on Partial Evaluation and SemanticsBased Program Manipulation (PEPM
, 1995
"... We investigate the soundness of a specialisation technique due to Scherlis, expression procedures, in the context of a higherorder nonstrict functional language. An expression procedure is a generalised procedure construct providing a contextually specialised definition. The addition of expression ..."
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Cited by 8 (2 self)
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We investigate the soundness of a specialisation technique due to Scherlis, expression procedures, in the context of a higherorder nonstrict functional language. An expression procedure is a generalised procedure construct providing a contextually specialised definition. The addition of expression procedures thereby facilitates the manipulation and specialisation of programs. In the expression procedure approach, programs thus generalised are transformed by means of three key transformation rules: composition, application and abstraction. Arguably, the most notable, yet most overlooked feature of the expression procedure approach to transformation, is that the transformation rules always preserve the meaning of programs. This is in contrast to the unfoldfold transformation rules of Burstall and Darlington. In Scherlis' thesis, this distinguishing property was shown to hold for a strict firstorder language. Rules for callbyname evaluation order were stated but not proved correct....
Optimizing aggregate array computations in loops
 ACM Transactions on Programming Languages and Systems
, 2005
"... An aggregate array computation is a loop that computes accumulated quantities over array elements. Such computations are common in programs that use arrays, and the array elements involved in such computations often overlap, especially across iterations of loops, resulting in significant redundancy ..."
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Cited by 6 (1 self)
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An aggregate array computation is a loop that computes accumulated quantities over array elements. Such computations are common in programs that use arrays, and the array elements involved in such computations often overlap, especially across iterations of loops, resulting in significant redundancy in the overall computation. This paper presents a method and algorithms that eliminate such overlapping aggregate array redundancies and shows analytical and experimental performance improvements. The method is based on incrementalization, i.e., updating the values of aggregate array computations from iteration to iteration rather than computing them from scratch in each iteration. This involves maintaining additional values not maintained in the original program. We reduce various analysis problems to solving inequality constraints on loop variables and array subscripts, and we apply results from work on array data dependence analysis. For aggregate array computations that have significant redundancy, incrementalization produces drastic speedup compared to previous optimizations; when there is little redundancy, the benefit might be offset by cache effects and other factors. Previous methods for loop optimizations of arrays do not perform incrementalization, and previous techniques for loop incrementalization do not handle arrays. 1