This paper proposes an efficient technique for con-extsensitive pointer analysis that is applicable to real C programs. For efficiency, we summarize the effects of procedures using partial tran$er func(ions. A partial...
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Compile-time type information should be valuable in efficient compilation of statically typed functional languages such as Standard ML. But how should type-directed compilation work in real compilers, and how much per...
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Dynamic dispatching is a major source of run-time overhead in object-oriented languages, due both to the direct cost of method lookup and to the indirect effect of preventing other optimizations. To reduce this overhe...
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ISBN:
(纸本)9780897916974
Dynamic dispatching is a major source of run-time overhead in object-oriented languages, due both to the direct cost of method lookup and to the indirect effect of preventing other optimizations. To reduce this overhead, optimizing compilers for object-oriented languages analyze the classes of objects stored in program variables, with the goal of bounding the possible classes of message receivers enough so that the compiler can uniquely determine the target of a message send at compile time and replace the message send with a direct procedure call. Specialization is one important technique for improving the precision of this static class information: by compiling multiple versions of a method, each applicable to a subset of the possible argument classes of the method, more precise static information about the classes of the method's arguments is obtained. Previous specialization strategies have not been selective about where this technique is applied, and therefore tended to significantly increase compile time and code space usage, particularly for large applications. In this paper, we present a more general framework for specialization in object-oriented languages and describe a goal-directed specialization algorithm that makes selective decisions to apply specialization to those cases where;it provides the highest benefit. Our results show that our algorithm improves the performance of a group of sizeable programs by 65% to 275% while increasing compiled code space requirements by only 4% to 10%. Moreover, when compared to the previous state-of-the-art specialization scheme, our algorithm improves performance by 11% to 67% while simultaneously reducing code space requirements by 65% to 73%.
We present the first profiler for a compiled, non-strict, higher-order, purely functional language capable of measuring time as well as space usage. Our profiler is implemented in a production-quality optimising compi...
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ISBN:
(纸本)9780897916929
We present the first profiler for a compiled, non-strict, higher-order, purely functional language capable of measuring time as well as space usage. Our profiler is implemented in a production-quality optimising compiler for Haskell, has low overheads, and can successfully profile large applications. A unique feature of our approach is that we give a formal specification of the attribution of execution costs to cost centres. This specification enables us to discuss our design decisions in a precise framework. Since it is not obvious how to map this specification onto a particular implementation, we also present an implementation-oriented operational semantics, and prove it equivalent to the specification.
Every problem has a context, which can include l community and culture implementation constraints language and system and probably other things too. A good design will take its context into account. If the culture dem...
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ISBN:
(纸本)0897917219
Every problem has a context, which can include l community and culture implementation constraints language and system and probably other things too. A good design will take its context into account. If the culture demands it, that may mean, for example, using object-oriented techniques where they don't really apply or not using them in a case that seems to cry out for them. It may mean choosing a programminglanguage without regard for its usual advantages or disadvantages. It may mean using a set of tools that some people may find cumbersome or outdated, It may call for all kinds of things that may seem nonsensical when viewed in isolation. But software systems do not exist in isolation. They would not be systems if they did. Any useful system must take its context into account. Unless we can answer the question "Good for what?" we cannot say whether or not a design is good.
Reflective programminglanguages are those where users' programs are allowed to customize in an organized way the behavior of the language to their own needs. For ten years now, most of the work on reflection revo...
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Traditionally research in dependence testing considered the most general linear subscripted DO loops permitted by standard Fortran. However, the existing program transformations are discussed in isolation without deve...
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Traditionally research in dependence testing considered the most general linear subscripted DO loops permitted by standard Fortran. However, the existing program transformations are discussed in isolation without developing a unified and formal theory for the most general loops. Consequently all the available parallelism in the serial programs is not exploited by the existing techniques;for example, the existing techniques can neither completely remove the output dependence cycles nor recognize all types of reduction loops. In this paper, based on the empirical studies of Goff et al. (Proc. acmsigplan '91 conference on programminglanguagedesign and implementation, Toronto, Ontario, Canada, June 26-28, 1991, pp. 15-29), first we consider a DO loop model which encompasses 97% of the practical Fortran DO loops. By analyzing their dependence characteristics, we develop the formal theory for the application of various parallelizing transformations, specifically the dependence cycle breaking transformations. By this formalization, we contribute the following useful results: (1) define the scope of the existing cycle breaking techniques and illustrate the shortcomings in them;(2) present the dependence characteristics of reduction loops, which will help in designing general reduction loop recognition algorithms in contrast to the existing pattern matching techniques;and (3) propose a new transformation called node replication and prove that by applying this transformation all the output dependence cycles can be completely removed. Finally, we discuss how the most general linear subscripted DO loops can be converted into the above-mentioned loop model, showing that the results presented in this paper are applicable to ah the linear subscripted DO loops permitted by standard Fortran. (C) 1995 Academic Press, Inc.
This paper describes the design and implementation of a query engine that provides extended SQL-based access to the data managed by an object-oriented database system. This query engine allows extended SQL queries to ...
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Constraint programming (CP) is in its substance non-algorithmic programming, not last because it is often being applied to problems for which no efficient algorithms exist. A not immediately obvious consequence of thi...
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The proceedings contain 30 papers on programminglanguages. Topics include languagedesign, data structures, codes, mathemtical techniques, errors, error correction, computation theory, program compiling and program o...
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ISBN:
(纸本)089791662X
The proceedings contain 30 papers on programminglanguages. Topics include languagedesign, data structures, codes, mathemtical techniques, errors, error correction, computation theory, program compiling and program optimization.
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