Yang, W., "A new algorithm for semantics-based program integration," Ph.D. Thesis, Department of Computer Sciences, University of Wisconsin, Madison, WI (1990).  Home/Search   Document Not in Database   Summary   Related Articles   Check

....merged such that the conditions stated above are satisfied. Horwitz, Prins, and Reps used program slicing to identify the preserved and changed behaviors between programs. There are three reported algorithms for program integration: HPR algorithm [HPR88a] Reps algorithm [Rep90] Yang s algorithm [Yan90]. Figure 1 gives a schematic diagram comparing the internal representations used by these algorithms. As is obvious, the proof of correctness of the slicing and integration algorithms and of properties of their results depend very strongly on the internal representation of their programs and the ....

....integration will satisfy the semantic graph integration theorem. This implies that HPR slicing and integration algorithms can be used with graph representations for programs other than PDGs for which the slicing axiom hold. A candidate for such a replacement is Yang s program representation graph [Yan90]. Restating HPR s integration theorem by abstracting the specific representation (PDG) and interpretation (operational semantics) has the benefit that this algorithm may now be used for integrating versions of any artifact that may be represented as graph. Further, for every interpretation ....

Wuu Yang. A new algorithm for semantics-based program integration. PhD thesis, University of Wisconsin Madison, WI, August 1990. 24

....be turned into an efficient nonlinear matching algorithm, where each equality check takes unit time. iv) A new hash free basic block optimization by value numbering [2, 8] is given, which leads to a faster solution to the program equivalence problem used in integration by Yang, Horwitz, and Reps [27, 28]. v) Although the main parts of algorithms for global constant propagation [26] global common subexpression detection [4] and code motion [9] do not use hashing, the preprocessing portions for each of these algorithms do. Such hashing can be eliminated without penalty by efficient construction ....

....then the many function coarsest partition problem is solved by Hopcroft s algorithm in time Q(k V log V ) and space Q(k V ) in the worst case, and by multiset dag discrimination in time O(k V ) and space O( V ) 3.5. The Sequence Congruence Problem The sequence congruence problem [27, 28] arises in the context of program integration. It asks how to partition program components into classes whose members have equivalent execution behaviors. The algorithm presented in [27, 28] solves this problem in two phases: the program components are first partitioned with respect to the flow ....

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Yang, W., "A new algorithm for semantics-based program integration," Ph.D. Dissertation, TR 962, Computer Sciences Dept., Univ. of Wisconsin, Madison, WI, August 1990. - 30 - -- --

....instance, Griswold s prototype [20, 24] Opdyke s refactory [47] and REFINE Cobol [41] all use the AST to display or output the source. Rederiving source code from other representations is more difficult. For example, the PDG has been used as the basis of an algorithm for merging program versions [29, 58, 59]. However, the PDG only stores dependences between computationally related program components [17] ignoring explicit statement order. To reconstitute the merged program (as an AST) all operations must first be ordered. Unfortunately, this ordering step is NP complete, and may also fail if the ....

W. Yang. A New Algorithm for Semantics-Based Program Integration. PhD thesis, University of Wisconsin, August 1990. Computer Sciences Technical Report No. 962.

....values without changing them. Such a change, for instance, is the first step to allowing inlined text to be extracted into a procedure: its parameters are passed by a transitive assignment. This notion of equivalent meaning is rigorously applied by the Sequence Congruence algorithm of Wuu Yang [Yang 90] which computes equivalence classes of equivalent 72 programs or subprograms. Members of an equivalence class, when given identical inputs, terminate with their visible variables in the same state. Although Yang s definition of the Sequence Congruence algorithm uses a variant of the PDG called ....

....valuable subcase of sequence congruence is data congruence, which is the property that two vertices in the same partition have after just phases (1) and (2) are completed. The algorithm can be extended by using a special rewrite pass to handle the transitivity of assigning one variable to another [Yang 90, p. 62] The extension is necessary because the basic algorithm does not recognize assignment as an operation. By definition, subgraphs of a PDG may be modified by the substitution of sequencecongruent vertices without changing a PDG s meaning. For example, a vertex and its incoming edges can be ....

W. Yang. A New Algorithm for Semantics-Based Program Integration. PhD dissertation, University of Wisconsin, August 1990. Computer Sciences Technical Report No. 962.

....each subtree equality check takes unit time. The method is also used to perform basic block optimizations (previously carried out by hashing value numbers [11,3] without hashing. It also leads to a faster solution to the program equivalence problem used in integration by Yang, Horwitz, and Reps [40,41]. # Although the main parts of algorithms for global constant propagation [38] global common subexpression detection [5] and code motion [12] do not use hashing, the preprocessing portions for each of these algorithms do. Such hashing can be eliminated without penalty by efficient ....

....input instances. Our approach is likely to be more efficient than his, since our pointer based dag discrimination avoids the numeric representation that is needed in order to make direct use of the algorithm found in [22] 3.5. The Sequence Congruence Problem The sequence congruence problem [40,41] arises in the context of program integration. The problem is how to partition program components into classes whose members have equivalent execution behavior. The algorithm presented in [40,41] solves this problem in two phases: the program components are first partitioned with respect to a ....

[Article contains additional citation context not shown here]

Yang, W., "A new algorithm for semantics-based program integration," Ph.D. Dissertation, TR 962, Computer Sciences Dept., Univ. of Wisconsin, Madison, WI, August 1990.

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Yang, W., "A new algorithm for semantics-based program integration," Ph.D. Thesis, Department of Computer Sciences, University of Wisconsin, Madison, WI (1990).

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Wuu Yang. A new algorithm for semantics-based program integration. PhD thesis, University of Wisconsin Madison, WI, August 1990. 24

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Yang, W., "A new algorithm for semantics-based program integration," Ph.D. dissertation and Tech. Rep. TR-962, Computer Sciences Department, University of Wisconsin, Madison, WI (August 1990). - 32 - ###################################################################################

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Yang, W., "A new algorithm for semantics-based program integration, " Ph.D. Thesis, Department of Computer Sciences, University of Wisconsin, Madison, WI (1990).

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Yang90. Yang, W., A new algorithm for semantics-based program integration, Ph.D. dissertation and Tech. Rep. TR-962, Computer Sciences Department, University of Wisconsin, Madison, WI (August 1990).

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