T. E. Cheatham, G. H. Holloway, and J. A. Townley, Symbolic evaluation and the analysis of programs, IEEE Trans. on Software Engineering 5 (1979), no. 4, 403-417.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....In Section 4 we survey related work. In Section 5 we conclude this paper and describe future work. 2 Symbolic Evaluation Symbolic evaluation is an advanced static program analysis in which symbolic expressions are used to denote the values of program variables and computations (cf. e.g. [6]) A path condition describes the impact of the program s control flow onto the values of variables and the condition under which control flow reaches a given program point. In the past symbolic evaluation has been successfully applied to the reaching definitions problem [2] to worst case ....

T. E. Cheatham, G. H. Holloway, and J. A. Townley, Symbolic evaluation and the analysis of programs, IEEE Trans. on Software Engineering 5 (1979), no. 4, 403-417.

....or repetitive statements in order to be concise. Treatment of intraprocedural symbolic analysis of Ada programs can be found in [3] Symbolic evaluation is a form of static program analysis in which symbolic expressions are used to denote the values of program variables and computations (cf. e.g. [5]) In addition a path condition describes the impact of the program s control flow onto the values of variables and the condition under which control flow reaches a given program point. The underlying program representation for symbolic evaluation is usually the control flow graph (CFG) a ....

T. E. Cheatham, G. H. Holloway, and J. A. Towriley. Symbolic Evaluation and the Analysis of Programs. IEEE Trans. on Software Engineering, 5(4):403-417, July 1979.

....be incorporated in existing Ada compilers. In fact we have integrated a prototype into GNAT for our purposes. 2 Symbolic Evaluation Symbolic evaluation is a form of static program analysis in which symbolic expressions are used to denote the values of program variables and computations (cf. e.g. [5]) In addition a path condition describes the impact of the program s control flow onto the values of variables and the condition under which control flow reaches a given program point. Conditions and the Control Flow Graph An edge e = B , B) of the CFG has assigned a condition Cond(B ,B) which ....

T. E. Cheatham, G. H. Holloway, and J. A. Towriley. Symbolic evaluation and the analysis of programs. IEEE Trans. on Software Engineering, 5(4):403-417, July 1979.

....is algebraically simplified and becomes the new symbolic value of the variable on the left hand side. Figure 2 contains the final symbolic evaluation of the C code in the figure. Research in the use of symbolic evaluation for program analysis has been carried out by several research groups[Ho78] [ChHoTo79], KeEc85] It has been used in many program analysis studies [YoTa88] It is a general way to figure out the dynamic behavior of a program, but not all topics and constructions can be handled the same way with this technique. Following problems remain or require 7 at least special treatment. ....

T. E. Cheatham, Jr, G. H. Holloway, J. A. Townley, Symbolic Evaluation and the Analysis of Programs, IEEE Trans. on Software Engineering, Vol. SE-5, No. 4, July 1979.

....or the upper bound WCET # # exit # entry # 1 # 2 (#ld n# 1) # 2 # 3 # 4 # 5 ) 5.1. Symbolic Evaluation. Symbolic evaluation is a form of static program analysis in which symbolic expressions are used to denote the values of program variables and computations (cf. e.g. CHT79, Plo80, CR81, Sch96, BFS00, BB98, BBS99, BBS00, FS97] In addition a path condition describes the impact of the program s control flow onto the values of variables and the condition under which control flow reaches a given program point. 5.1.1. Program State and Context. The state S of a ....

....program state S, vset(S, v, n) returns the state that is implied by setting the value of v in S to n. 5.1.2. Expressions and Simple Statements. Expressions are evaluated symbolically in such a straightforward manner that we do not elaborate on details. The interested reader is referred to [CHT79, FS97] for a more complete treatment of this issue for certain programming languages. Examples for simple statements are given in Table 6. We use val( for denoting symbolic evaluation of program contexts. Of course, details of evaluating simple statements may di#er from programming ....

Thomas E. Cheatham, Glenn H. Holloway, and Judy A. Townley, Symbolic evaluation and the analysis of programs, IEEE Trans. on Software Engineering 5 (1979), no. 4, 403--417. 16, 16

.... Delta 4 or the upper bound WCET exit entry 1 2 (bldnc 1) Delta ( 2 3 4 5 ) 5.1. Symbolic Evaluation Symbolic evaluation is a form of static program analysis in which symbolic expressions are used to denote the values of program variables and computations (cf. e.g. (Cheatham et al. 1979; Ploedereder, 1980; Clarke and Richardson, 1981; Scholz, 1996; Blieberger et al. 2000b; Blieberger and Burgstaller, 1998; Blieberger et al. 1999; Blieberger et al. 2000a; Fahringer and Scholz, 1997) In addition a path condition describes the impact of the program s control flow onto the ....

....; pk ] v : E [vset(S1 ; v; val(E; S1) p1 ] Delta Delta Delta [ vset(Sk ; v; val(E; Sk ) pk ] 5.1.2. Expressions and Simple Statements Expressions are evaluated symbolically in such a straightforward manner that we do not elaborate on details. The interested reader is referred to (Cheatham et al. 1979; Fahringer and Scholz, 1997) for a more complete treatment of this issue for certain programming languages. Examples for simple statements are given in Table VI. We use val( for denoting symbolic evaluation of program contexts. Of course, details of evaluating simple statements may ....

Cheatham, T. E., G. H. Holloway, and J. A. Townley: 1979, `Symbolic Evaluation and the Analysis of Programs'. IEEE Trans. on Software Engineering 5(4), 403--417.

....In Section 4 we survey related work. In Section 5 we conclude this paper and describe future work. 2 Symbolic Evaluation Symbolic evaluation is an advanced static program analysis in which symbolic expressions are used to denote the values of program variables and computations (cf. e.g. [6]) A path condition describes the impact of the program s control flow onto the values of variables and the condition under which control flow reaches a given program point. In the past symbolic evaluation has been successfully applied to the reaching definitions problem [2] to worst case ....

T. E. Cheatham, G. H. Holloway, and J. A. Townley, Symbolic evaluation and the analysis of programs, IEEE Trans. on Software Engineering 5 (1979), no. 4, 403--417.

....abstract interpretation to discover program properties such as values of expressions, relationships between symbolic expressions, etc. Symbolic analysis requires the ability to represent and manipulate unknown symbolic terms. Among several expression representations, a normal form is often used [7, 9, 22]. The advantage of a normal form is that it gives the same representation for congruent expressions. In addition, symbolic expressions encountered in array data flow analysis and dependence analysis are mostly integer polynomials. Operations on integer polynomials, such as the comparison of two ....

....can be implemented rather efficiently. A canonical normal form is used to represent the predicates. Pattern matching under a normal form is easier than under arbitrary forms. Both the conjunctive normal form (CNF) and the disjunctive normal form (DNF) have been widely used in program analysis [7, 9]. These cited works show that negation operations are expensive with both CNF and DNF. This fact was also confirmed by our previous experiments using CNF [20] Negation operations occur not only due to ELSE branches, but also due to GAR and GARWD operations elsewhere. Hence, we design a new normal ....

T.E. Cheatham Jr., G.H. Holloway, and J.A. Townley. Symbolic evaluation and the analysis of programs. IEEE Trans.on Software Engineering, 5(4):402--417, July 1979.

....or repetitive statements in order to be concise. Treatment of intraprocedural symbolic analysis of Ada programs can be found in [3] Symbolic evaluation is a form of static program analysis in which symbolic expressions are used to denote the values of program variables and computations (cf. e.g. [5]) In addition a path condition describes the impact of the program s control flow onto the values of variables and the condition under which control flow reaches a given program point. The underlying program representation for symbolic evaluation is usually the control flow graph (CFG) a ....

T. E. Cheatham, G. H. Holloway, and J. A. Townley. Symbolic Evaluation and the Analysis of Programs. IEEE Trans. on Software Engineering, 5(4):403--417, July 1979.

....that arise at the head of each loop can be considered to be loop invariants but ones that have been automatically inferred by our system, not provided by the user. Because our domain of descriptors is finite, this invariant synthesis problem has a di#erent character than those used in [4, 29, 30, 28] (i.e. in our work, the invariants are generated in the course of performing an iterative fixed point computation) Furthermore, there is nothing special about the program points at the heads of loops; they are treated in exactly the same way that any other program point is treated during the ....

T.E. Cheatham, Jr., G.H. Holloway, and J.A. Townley. Symbolic evaluation and the analysis of programs. IEEE Trans. on Softw. Eng., 5(4):402--417, 1979.

....studied. Good surveys can be found in (Alt et al. 1996; Mueller, 1997; Ottosson and Sjoedin, 1997; Li et al. 1996; Li et al. 1995; Healy et al. 1995; Arnold et al. 1994; Nilsen and Rygg, 1995; Liu and Lee, 1994; Hennessy and Patterson, 1990) 3. Symbolic Evaluation Symbolic evaluation 3 (Cheatham et al. 1979; Ploedereder, 1980; Fahringer and Scholz, 1997; Fahringer and Scholz, 1999) z is a constructive description of the semantics of a program. Moreover, symbolic evaluation is not merely an arbitrary alternative semantic description of a program. As in the relationship between arithmetic and algebra ....

Cheatham, T., H. Holloway, and J. Townley: 1979, `Symbolic Evaluation and the Analysis of Programs'. IEEE Trans. Software Eng. 5(4), 403--417.

....world. But models are not reality Validation to a model is not validation to the real world. 11. Computing is about insight. But let us be clear about the process. We are not interested in the codes per se. Richard Hamming said it best: The purpose of computing is insight, not numbers [24]. Insight is a very elusive commodity and may take years to develop. Insight is what the scientist or engineer counts on to guide her his research. Nobel prizes are given for insight and not necessarily details. 12. Artists need insights, too. A story for the ages. Technical disciplines are not ....

....257 270. Plenum, 1978. 22] Carl A. Gunter. Semantics of Programming Languages: Structures and Techniques. Foundations of Computing. MIT Press, 1992. 23] John Gustafson. Computational verifiability and feasibility of the asci program. IEEE Computational Science Engineering, Jan. Mar. 1998. [24] R. W. Hamming. Numerical methods for scientists and engineers. McGraw Hill, 1973. 25] Les Hatton. Safer C: Developing Software for HighIntegrity and Safety Critical Systems. McGraw Hill, 1995. 26] Les Hatton. The T experiments: Errors in scientific software. IEEE Computational Science and ....

T. E. Cheatham, G. H. Holloway, and T. A. Townley. Symbolic evaluation and analysis of programs. Trans. on Soft. Engr., 5:402--417, 1979.

....can be implemented rather efficiently. A canonical normal form is used to represent the predicates. Pattern matching under a normal form is easier than under arbitrary forms. Both the conjunctive normal form (CNF) and the disjunctive normal form (DNF) have been widely used in program analysis [21, 5]. These cited works show that negation operations are expensive with both CNF and DNF. This fact was also confirmed by our previous experiments using CNF [11] Negation operations occur not only due to ELSE branches, but also due to GAR and GARWD operations elsewhere. Hence, we design a new normal ....

Jr T.E. Cheatham, G.H. Holloway, and J.A. Townley. Symbolic evaluation and the analysis of programs. IEEE Trans.on Software Engineering, 5(4):402--417, July 1979.

....of programs to be exploited by optimizing and parallelizing compilers. This can be achieved by specifying the relationship between actual values and their descriptions and by establishing a connection between the operations on the actual values and those on the corresponding abstract values [Cheatham et al. 1979; Clarke and Richardson 1981] This theory of semantics approximation is called abstract interpretation [Cousot and Cousot 1977; 1992] The term approximate does not imply any possibilities of incorrectness, but rather the lack of full information is meant. Roughly speaking, in the method of ....

Cheatham, T. E., Jr., Holloway, G. H., and Townley, J. A. 1979. Symbolic evaluation and the analysis of programs. IEEE Trans. Softw. Eng. 5, 4 (July), 402--417.

....can be implemented in an efficient way. We define a new canonical form to represent predicates in order to simplify pattern matching needed to check whether two predicates are identical. Both conjunctive normal form (CNF) and disjunctive normal form (DNF) have been widely used in program analysis [26, 6]. These cited works show that negation operations are expensive with both CNF and DNF. Our previous experiments using CNF [12] also confirm their observations. Negation operations occur not only due to ELSE branches, but also due to GAR and GARWD operations elsewhere. Hence, we design a new ....

....interpretation techniques to discover program properties such as values of expressions, relationships between symbolic expressions, etc. Symbolic analysis requires to represent and manipulate unknown symbolic terms. A symbolic analyzer can adopt a certain normalized form to represent expressions [26, 6, 13]. The advantage of such a normalized form is that it gives the same representation for two congruent expressions, i.e. they always have the same value. For example, x Delta (x 1) and x x 2 are congruent expressions. In addition, symbolic expressions encountered in array data flow analysis and ....

Cheatham, T.E. Jr, Holloway, G.H., Townley, J.A. (1979). Symbolic Evaluation and the Analysis of Programs. IEEE Trans.on Software Engineering, July, 5(4):402-417.

No context found.

CHT79. T. E. Cheatham, H. Holloway, and J. A. Townley, Symbolic evaluation and the analysis of programs, IEEE Trans. Software Eng. 5 (1979), no. 4, 402--317.

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