Y. A. Liu and G. Gomez. Automatic accurate timebound analysis for high-level languages. Technical Report TR508, Indiana University, 107 S. Indiana Ave., Bloomington, IN 47405-7000, USA, April 1998.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....determine an upper bound on the longest path of the program. Techniques include treebased approaches [10, 4] or path based approaches [8, 12, 13] E#orts on WCET analysis are on determining the e#ect of advanced processor features like cache, branch prediction and pipelines and their interactions [9, 6, 5, 7], However, these approaches are very complex as the processors themselves become more di#cult to predict. An alternative approach to static analysis is by measurement. In this approach the code is run under exhaustive test conditions and the longest execution time recorded. Both approaches have ....

Y. A. Liu and G. Gomez. Automatic accurate time--bound analysis for high--level languages. In Frank Muller, Azer Bestravros, et al., editors, Proceedings of the ACM SIGPLAN Workshop on Languages, Compilers and Tools for Embedded Systems (LCTES'98), Lecture Notes in Computer Science, pages 31--40, Montreal Canada, June 19--20 1998. ACM SIGPlAN, Springer--Verlag.

....bound for a program is achieved by (1) composing a suitable inverse size function with the abstract interpretation of the step counting version of the program and (2) taking the term model. Program transformation is then used to simplify this initial cost bound as much as possible. Liu and Gomez [7] propose a method based on Rosendahl s work in which they use advanced program transformation techniques to make the cost bound more e#cient and more accurate. Both methods requires the user to define the abstraction from data to data size. However, with dependent types, measures can be expressed ....

Yanhong Annie Liu and Gustavo Gomez. Automatic accurate time-bound analysis for high-level languages. In Frank Mueller and Azer Bestavros, editors, Proceedings of LCTES'98, number 1474 in LNCS, pages 31--40, Montreal, Canada, June 1998. Springer-Verlag.

....bound for a program is achieved by (1) composing a suitable inverse size function with the abstract interpretation of the step counting version of the program and (2) taking the term model. Program transformation is then used to simplify this initial cost bound as much as possible. Liu and Gomez [5] propose a method based on Rosendahl s work in which they use advanced program transformation techniques to make the cost bound more e#cient and more accurate. Both methods requires the user to define the abstraction from data to data size. However, with dependent types, measures can be expressed ....

Yanhong Annie Liu and Gustavo Gomez. Automatic accurate time-bound analysis for high-level languages. In Frank Mueller and Azer Bestavros, editors, Proceedings of the ACM SIGPLAN

....notion of closedness of [5] during partial evaluation. However, this property is not guaranteed when stronger notions of closedness are considered during partial evaluation (e.g. the recursive closedness of [5] or when some partitioning techniques are used (as in conjunctive partial deduction [23]) According to Def. 11, the equations of Example 6 are not closed due to calls like S(x : app (app x s y) z) However, this is not a problem. We can simplify constructor rooted calls using the following (straightforward) properties: C(x) 0, for all x 2 V (1) C(t) C(t 1 ) C(tn ) ....

Y. A. Liu and G. Gomez. Automatic Accurate Time-Bound Analysis for High-Level Languages. In Proc. of ACM SIGPLAN Workshop on Languages, Compilers, and Tools for Embedded Systems, pages 31-40. Springer LNCS 1474, 1998.

....declarative programs. For logic programs, 13] introduces a method for the (semi )automatic analysis of the worst case cost of a large class of logic programs, including nondeterminism and the generation of multiple solutions via backtracking. Regarding eager (call by value) functional programs, [24] describes a general approach for time bound analysis of programs. Essentially, it is based on the construction of time bound functions which mimic the original functions but compute the associated cost of evaluations. The techniques of [24] cannot be easily adapted to lazy (call by name) ....

....Regarding eager (call by value) functional programs, 24] describes a general approach for time bound analysis of programs. Essentially, it is based on the construction of time bound functions which mimic the original functions but compute the associated cost of evaluations. The techniques of [24] cannot be easily adapted to lazy (call by name) functional languages since cost criteria are not usually compositional. A similar approach can be found in [30] where a step counting version of a functional program is produced automatically. This version, when called with the same arguments as ....

[Article contains additional citation context not shown here]

Y. A. Liu and G. Gomez. Automatic Accurate Time-Bound Analysis for High-Level Languages. In Proc. of ACM SIGPLAN Workshop on Languages, Compilers, and Tools for Embedded Systems, pages 31--40. Springer LNCS 1474, 1998.

....digital cameras, automobiles, ight navigation systems etc. Unlike general purpose processors, embedded processors are designed and optimized for speci c (classes of) applications [13] Embedded systems are constrained by limited on chip program memory [2] real time performance requirements [18, 27] and low power consumption demands. The evaluation criteria for embedded processors are di erent from those of general purpose processors. The following criteria are typically used while comparing embedded processors [35] Performance: The cost performance ratio of embedded systems is measured in ....

Y. A. Liu and Gustavo Gomez. Automatic accurate time-bound analysis for high-level languages. In ACM SIGPLAN Workshop on Languauges, Compilation and Tools for Embedded Systems, pages 31-40, June 1998.

....ways to save power through software optimizations This paper also attempts to study the effect of code restructuring transformations on power consumption. It is clear from the above discussion that embedded systems are constrained by limited on chip memory [2] real time performance requirements [16, 23] and low power consumption demands, in particular with the mobile embed1 ded systems. Traditionally, embedded processors and systems are programmed using assembly language, in order to meet the hard performance constraints and limited program memory. But, programming large complex applications in ....

Y. A. Liu, and Gustavo Gomez. Automatic accurate time-bound analysis for high-level languages. In Proceedings of the ACM SIGPLAN 1998 Workshop on Languages, Compilers, and Tools for Embedded Systems, pp. 31-40, Montreal, Canada, June 1998.

....these methods applied in vpo could be used in other compilers or on assembly or machine code les as well. 2. Related Work Previous work to bound the number of loop iterations has used abstract interpretation (Ermedahl and Gustafsson, 1997) and symbolic execution (Lundqvist and Stenstr om, 1998; Liu and Gomez, 1998) to automatically derive the number of loop iterations. These approaches are quite powerful, but e ectively requires simulating all paths of a loop for every loop iteration. Thus, they require signi cant analysis overhead, which would be undesirable when analyzing long running programs. Our work ....

Liu, Y. and G. Gomez: 1998, `Automatic Accurate Time-Bound Analysis for HighLevel Languages'. In: ACM SIGPLAN Workshop on Languages, Compilers, and Tools for Embedded Systems. pp. 31-40.

....for further execution. The computation is done by a linear programming approach. Second a phasing of tasks is introduced to eliminated infeasible task interactions. In Section 4.4 a simpler method is proposed. An approach which bases solely on the analysis of high level language is described in [10] by Liu and Gomez. To each procedure of the program under investigation a timing function is added, which returns additional to the original return value the time that was consumed by the function executed. The input parameters are limited to a known set of values. Combined with symbolic ....

Y. A. Liu and G. Gomez. Automatic accurate time-- bound analysis for high--level languages. In Muller et al. [11], pages 31--40.

....these methods applied in vpo could be used in other compilers or on assembly or machine code files as well. 2. Related Work Previous work to bound the number of loop iterations has used abstract interpretation (Ermedahl and Gustafsson, 1997) and symbolic execution (Lundqvist and Stenstrom, 1998; Liu and Gomez, 1998) to automatically derive the number of loop iterations. These approaches are quite powerful, but effectively requires simulating all paths of a loop for every loop iteration. Thus, they require significant analysis overhead, which would be undesirable when analyzing long running programs. Our work ....

Liu, Y. and G. Gomez: 1998, `Automatic Accurate Time-Bound Analysis for HighLevel Languages'. In: ACM SIGPLAN Workshop on Languages, Compilers, and Tools for Embedded Systems. pp. 31--40.

....derive loop bounds by means of a syntactical analysis has been proposed. They successfully use this technique together with timing analysis in order to reduce the work for the user, but they do no general path analysis in order to identify infeasible paths. In a recent work, Liu and Gomez [11] construct time bound functions for high level languages, using a technique related to ours. However, no concern is made for doing accurate low level timing analysis. In our method, the simulator uses a very simple domain where values can be either known or unknown. This domain performs quite well ....

Y. A. Liu and G. Gomez. Automatic Accurate Time-Bound Analysis for HighLevel Languages. Dept. of Computer Science, Indiana University, Technical Report TR-508, April 1998.

....paths [2, 11, 16, 18] However, they apply only to some classes of programs or use approximations that are too crude for the analysis. Also, separating the loop and path information from the rest of the analysis is in general less accurate than an integrated analysis [28] Liu and G omez [25] studied a general approach for automatic and accurate time bound analysis that combines methods and techniques studied in theory, languages, and systems. They call it a language based approach since it primarily exploits methods and techniques for static program analysis and transformation. ....

....there handles only first order functions. Being able to handle higher order functions is important for analyzing most functional languages and for analyzing methods in object oriented languages with inheritance. This paper extends the language based approach to a higherorder language. As before [25], the approach consists of transformations for building time bound functions in the presence of partially known input structures, symbolic evaluation of the time bound function based on input parameters, optimizations to make the analysis efficient as well as accurate, and measurements of ....

[Article contains additional citation context not shown here]

Y. A. Liu and G. G'omez. Automatic accurate time-bound analysis for high-level languages. In Languages, Compilers, and Tools for Embedded Systems, volume 1474 of Lecture Notes in Computer Science, pages 31--40. Springer-Verlag, June 1998.

....determine the maximum live heap space usage. Correctness of live heap analysis depends on keeping track of all references and reference counts meticulously. Summarizing the results of two branches into a single partially known structure that represents both results, as is done in timing analysis [19] and stack space and heap allocation analysis [27] does not work for live heap analysis because it would be impossible to keep track of reference counts accurately. So the result of a conditional whose test evaluates to uk is a separate entity, a join value, that points to both possible results ....

....formulating partially known inputs that represent classes of actual inputs is straightforward and can easily be done by a simple program. 7. RELATED WORK There has been a large amount of work on analyzing program cost or resource complexities, but the majority of it is on time analysis, e.g. [18, 24, 26, 19]. Stack space and heap allocation analysis [27] is similar to time analysis [19] Analysis of live heap space is di erent because it involves explicit analysis of the graph structure of the data. Most of the work related to analysis of space is on analysis of cache behavior, e.g. 28, 8] much ....

[Article contains additional citation context not shown here]

Y. A. Liu and G. Gomez. Automatic accurate time-bound analysis for high-level languages. In Proceedings of the ACM SIGPLAN

....the original program does. Nontermination occurs only if the recursive iterative structure of the original program depends on unknown parts of the given partially known input structures. Stack space and heap allocation analyses are similar to the time bound analysis proposed by Liu and G omez [34]. Constructions of the space and space bound functions for analyzing live heap space are based on reference counting [28] We are analyzing functional programs, so reference counting provides an accurate basis for the analysis. If imperative updates to data constructions are allowed (e.g. setcdr ....

....A simple variant of our analysis can determine the live heap space used by programs executed in this way. We may also use transformations that enable more accurate space bounds to be computed: lifting conditions, simplifying conditionals, and inlining nonrecursive functions, as described in [34]. These transformations should be applied to the original program before the space bound function is constructed. They may result in larger code size, but they allow subcomputations based on the same control conditions to be merged, leading to more accurate space bounds, which can be computed more ....

[Article contains additional citation context not shown here]

Y. A. Liu and G. Gomez. Automatic accurate time-bound analysis for high-level languages. In Proceedings of the ACM SIGPLAN

....worst case times (in milliseconds) with cache disabled. presence of low level e ects or precise analysis in their absence, and can be used for more accurate space bound analysis that helps addressing memory issues. 7 Related work and conclusion A preliminary version of this work appeared in [30]. An overview of comparison with related work in cost analysis appears in Section 2. Certain detailed comparisons have also been discussed while presenting our method. This section summarizes them, compares with analyses for loop bounds and execution paths in more detail, and concludes. Compared ....

Y. A. Liu and G. Gomez. Automatic accurate time-bound analysis for high-level 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, pages 31-40. Springer-Verlag, June 1998.

....as the original program, i.e. t( f 0 (x; r) t(f 0 (x) for r = f 0 (x) This can be checked after Step A.3. We guarantee this condition by simply dropping pieces of candidate auxiliary information for which it cannot be con rmed. Standard constructions for mechanical time analysis [75,83,49] can be used, although further study is needed, and it is being carried out for both time analysis [29] and space analysis [80] The trade o between time and space is a problem open for study. Suppose Step B.1 projects out the original value using 1st. With the above condition, in a similar way ....

Y. A. Liu and G. Gomez. Automatic accurate time-bound analysis for high-level 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, pages 31-40. Springer-Verlag, June 1998.

....and pruning produce programs that are at least as fast as the given program, but caching auxiliary information may result in a slower program on certain inputs. We can determine statically whether such information is cached in the nal program. If so, we can use time and space analysis [32, 54, 59, 60] to determine conservatively whether it is worthwhile to use and maintain such information. The trade o between time and space is an open problem for future study. Additional properties. Many dynamic programming algorithms can be further improved by exploiting additional properties, such as ....

Y. A. Liu and G. Gomez. Automatic accurate time-bound analysis for high-level 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, pages 31-40. Springer-Verlag, June 1998.

....the original program does. Nontermination occurs only if the recursive iterative structure of the original program depends on unknown parts of the given partially known input structures. Stack space and heap allocation analyses are similar to the time bound analysis proposed by Liu and G omez [34]. Constructions of the space and space bound functions for analyzing live heap space are based on reference counting [28] We are analyzing functional programs, so reference counting provides an accurate basis for the analysis. If imperative updates to data constructions are allowed (e.g. setcdr ....

....A simple variant of our analysis can determine the live heap space used by programs executed in this way. We may also use transformations that enable more accurate space bounds to be computed: lifting conditions, simplifying conditionals, and inlining nonrecursive functions, as described in [34]. These transformations should be applied to the original program before the space bound function is constructed. They may result in larger code size, but they allow subcomputations based on the same control conditions to be merged, leading to more accurate space bounds, which can be computed more ....

[Article contains additional citation context not shown here]

Y. A. Liu and G. G'omez. Automatic accurate time-bound analysis for high-level 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, pages 31--40. Springer-Verlag, June 1998.

....paths [2, 10, 15, 17] However, they apply only to some classes of programs or use approximations that are too crude for the analysis. Also, separating the loop and path information from the rest of the analysis is in general less accurate than an integrated analysis [27] Liu and G omez [24] studied a general approach for automatic and accurate time bound analysis that combines methods and techniques studied in theory, languages, and systems. They call it a language based approach since it primarily exploits methods and techniques for static program analysis and transformation. ....

....there handles only first order functions. Being able to handle higher order functions is important for analyzing most functional languages and for analyzing methods in object oriented languages with inheritance. This paper extends the language based approach to a higher order language. As before [24], the approach consists of transformations for building time bound functions in the presence of partially known input structures, symbolic evaluation of the time bound function based on input parameters, optimizations to make the analysis efficient as well as accurate, and measurements of ....

[Article contains additional citation context not shown here]

Y. A. Liu and G. G'omez. Automatic accurate time-bound analysis for high-level 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, pages 31--40. Springer-Verlag, June 1998.

....loop or recursion yields a much faster program. By expensive computations, we mean those that contribute to the asymptotic running time of a program. Work in program running time analysis, e.g. 83, 75] can help determine this; we have been studying such analyses in our own recent work as well [46, 32]. Power and limitation. Our work is the first in which reusing the previous result, caching intermediate results, and discovering auxiliary information are explicitly identified and put into a general framework. It unifies existing methods and allows domain specific properties to be effectively ....

....at Motorola) and making equality reasoning more systematic [89] In particular, equality reasoning on arithmetic operations and boolean operations are now performed using dedicated tools, Omega [66] and MONA [41] respectively. We have also been building a system, ALPA, for automated time analysis [46, 32] and 18 plan to use it in CACHET. Our optimizations for aggregate array computations [47] have also been automated. Our goal is to integrate all analyses and transformations in an open environment, and provide the user with options for different degrees of automation. CACHET has been used to ....

Y. A. Liu and G. G'omez. Automatic accurate time-bound analysis for high-level 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, pages 31--40. Springer-Verlag, June 1998.

....above. In each function definition, the former lifts conditions to the outmost scope that the test does not depend on, and the latter simplifies conditionals according to the lifted condition. These transformations are not needed for the examples in this paper. They are discussed further in [14]. 6 Implementation and experimentation We have implemented the analysis approach in a prototype system, ALPA (Automatic Language based Performance Analyzer) The implementation is for a subset of Scheme. The measurements and analyses are performed for source programs compiled with Chez Scheme ....

Y. A. Liu and G. Gomezes. Automatic accurate time-bound analysis for high-level languages. Technical Report TR 508, Computer Science Department, Indiana University, Bloomington, Indiana, Apr. 1998.

....and pruning produce programs that are as least as fast as the given program, but caching auxiliary information may result in a slower program on certain inputs. We can determine statically whether such information is cached in the final program. If so, we can use time and space analysis [29] to determine whether it is worthwhile to use and maintain such information. Many dynamic programming algorithms can be further improved by exploiting additional properties of the given problems [7] e.g. greedy properties. Our method is not specially aimed at discovering such properties. ....

Y. A. Liu and G. G'omez. Automatic accurate time-bound analysis for high-level 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, pages 31--40. Springer-Verlag, June 1998.

....and pruning produce programs that are as least as fast as the given program, but caching auxiliary information may result in a slower program on certain inputs. We can determine statically whether such information is cached in the final program. If so, we can use time and space analysis [27] to determine whether it is worthwhile to use and maintain such information. Many dynamic programming algorithms can be further improved by exploiting greedy properties of the given problems [7] Our method is not specially aimed at discovering such greedy properties. Nevertheless, it can maintain ....

Y. A. Liu and G. G'omez. Automatic accurate time-bound analysis for high-level 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. Springer-Verlag, June 1998.

No context found.

Y. A. Liu and G. Gomez. Automatic accurate timebound analysis for high-level languages. Technical Report TR508, Indiana University, 107 S. Indiana Ave., Bloomington, IN 47405-7000, USA, April 1998.

No context found.

Y.A. Liu and G. Gomez. Automatic accurate time-bound analysis for high-level languages. In Proc. of the ACM SIGPLAN 1998 Workshop on Languages, Compilers, and Tools for Embbeded Systems, pages 31--40. Springer LNCS 1474, 1998.

No context found.

Y. Liu and G. Gomez. Automatic accurate time-bound analysis for high-level languages. In Languages, Compilers and Tools for Embedded Systems (LCTES), 1998.

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