Joseph Hummel, Laurie J. Hendren, and Alexandru Nicolau. A language for conveying the aliasing properties of dynamic, pointer-based data structures. In Proc. 8th International Parallel Processing Symposium, Cancun, Mexico, April 26-29 1994.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....our language is primarily an interface to a static program analysis system. The sublanguage we use for specifying context speci c invariants is similar to the logic described in [1] which also explains the relationship with [8] A more general system used for dependence testing is described in [9]. There appears to be surprisingly little work on languages for describing precise e ects procedures with respect to the heap. The importance of procedure speci cations for pointer analysis was indicated in [14] A language for annotating software libraries is described in [6] E ects systems in ....

Joseph Hummel, Laurie J. Hendren, and Alexandru Nicolau. A language for conveying the aliasing properties of dynamic, pointer-based data structures. In #### ######## ## ### ### ############# ######## ########## #########, Cancun, Mexico, April 26-29 1994.

....machine. The smaller example took 283 seconds, and the larger one 497 seconds. Much of this time is spent in the closure computation routines, and in the case of the larger example the production of the waits for information from the large conflict graph. 5 Related Work The ASAP approach [HHN94b] uses three di#erent types of axiom to store information about the linkages in the structure. 1) #p p.RE1 #= p.RE2 2) #p #= q p.RE1 #= q.RE2 3) #p p.RE1 = p.RE2 where p, q are any path names and RE1,RE2 are regular expressions over the alphabet of fields . These axioms are then used ....

Joseph Hummel, Laurie J Hendren, and Alexandru Nicolau. A language for conveying the aliasing properties of dynamic, pointer-based data structures. In Proceedings of the 8th International Parallel Processing Symposium, April 1994.

....interprocedural analyses that infer one level of referencing relationships, but are not suciently precise to track must aliases of heap objects for programs with destructive updates of more complex data structures. The ADDS and ASAP languages allow programmers to express data structure properties [24, 25, 21]. This work uses data structure invariants to enable compiler optimizations, but, unlike our role analysis, does not verify that operations on data structures preserve these invariants [23] Several researchers have developed annotation languages to enable the separate analysis of multiple ....

Joseph Hummel, Laurie J. Hendren, and Alexandru Nicolau. A language for conveying the aliasing properties of dynamic, pointer-based data structures. In Proceedings of the 8th International Parallel Processing Symposium, Cancun, Mexico, April 26-29 1994.

....to track must aliases of heap objects for programs with destructive updates of more complex data structures. The ADDS data structure description language [49] uses declarations of unique pointers and independent data structure dimensions to communicate data structures invariants. Later systems [50, 45] replace these constraints with reachability axioms. None of these systems has a concept of a role which depends on aliasing of an object from other objects. These systems use sound techniques to apply the data structure invariants for parallelization and general dependence testing but do not ....

Joseph Hummel, Laurie J. Hendren, and Alexandru Nicolau. A language for conveying the aliasing properties of dynamic, pointer-based data structures. In Proceedings of the 8th International Parallel Processing Symposium, Cancun, Mexico, April 26-29 1994.

....Model I have been working with analysing a fairly restricted programming language that manipulates these structures. This approach seems common for research in this area, see [CCG96a] and [CC96] although some work with fairly unrestricted versions of languages such as C, for example in [HHN94] To illustrate the description there is a fragment of typical code in Fig. 1 The code works with one global data structure. Data elements are accessed via pathnames, which are 2 main (Tree v) Init(v l) Traverse(v l) Init(Tree i) if (i= NULL) return; i l = i l; i r = ....

Joseph Hummel, Laurie J Hendren, and Alexandru Nicolau. A language for conveying the aliasing properties of dynamic, pointer-based data structures. In Proceedings of the 8th International Parallel Processing Symposium, April 1994.

....is your goal it makes sense to restrict the structures to ones with a unique normal form. It should be mentioned that the group itself is quite a specialised concept, for example all directions must have inverses, which would exclude one way directed graphs. 2. 4 ASAP structures The ASAP approach [11] describes a structure as a set of axioms that hold between certain paths through the structure. An axiom can be one of the three forms: 8p; p:RE1 P:RE2 8p q; p:RE1 q:RE2 8p; p:RE1 = p:RE2 3 Here RE1 and RE2 are regular expressions over the language of directions. The approach is ....

Joseph Hummel, Laurie J Hendren, and Alexandru Nicolau. A language for conveying the aliasing properties of dynamic, pointer-based data structures. In Proceedings of the 8th International Parallel Processing Symposium, April 1994.

....unless the properties of the structures can be derived during the analysis of the code. The approach adopted here is for the programmer to infuse extra structural information in the description of the data structure, which is strictly adhered to by the program. We differ from the ASAP approach [3] in that the nodes of our structure need to be given unique names at compile time, so the description must provide information about when any pair of nodes are equal. The ASAP approach, however, allows incomplete information to be used, including identifying parts of the structure that cannot be ....

Joseph Hummel, Laurie J Hendren, and Alexandru Nicolau. A language for conveying the aliasing properties of dynamic, pointer-based data structures. In Proceedings of the 8th International Parallel Processing Symposium, April 1994.

....converted to produce an equivalent AG with the correct properties. We will demonstrate that this provides a sufficiently general and powerful framework for dependence analysis. Some methods of describing structures that we have considered so far are: Graph Types [KS93] Shape Types [FM97] ASAP [HHN94] and our format based descriptions [LA97] We can mechanically translate the structural information in the latter two description types into AGs. We cannot, at present, do the same for the earlier two types of descriptions. Programmer Supplied Structure Dependancy Dataflow Information ....

Joseph Hummel, Laurie J Hendren, and Alexandru Nicolau. A language for conveying the aliasing properties of dynamic, pointer-based data structures. In Proceedings of the 8th International Parallel Processing Symposium, April 1994.

....most optimizations. Since pointer analysis is a difficult problem, we will choose an existing algorithm that suits libraries. Information about pointer relationships is provided by the annotations (see Appendix A) using expressions to describe how a library function changes pointer relationships [11]. Liveness for heap objects We are reformulating liveness analysis to handle dynamically allocated heap objects. Initial experiments indicate that this is a very important optimization. Many of the specializations result in no op code that needs to be removed. The basic liveness analysis ....

Joseph Hummel, Alexandru Nicolau, and Laurie J. Hendren. A language for conveying the aliasing properties of dynamic, pointer-based data structures. In Howard Jay Siegel, editor, Proceedings of the 8th International Symposium on Parallel Processing, pages 208--216, Los Alamitos, CA, USA, April 1994. IEEE Computer Society Press.

....field. The ADDS description language is simple and its descriptive ability is limited by the small set of keywords. Hummel, Hendren and Nicolau later develop a more powerful 100 description language called abstract specification of alias properties (ASAP) to specify data structure properties[HHN94a] Each ASAP specification consists one or more axioms, which are provided by programmers or predefined by a language that supports higher level data structures. They also develop a framework to perform pointer analysis on programs with ASAP description using theorem proving [ HHN94b, HHN94c] ....

J. Hummel, L. Hendren and A. Nicolau. A Language for Conveying the Aliasing Properties of Dynamic, Pointer-Based Data Structure. In Proceedings of the 8th International Parallel processing Symposium, pages 208---216, Apr. 1994.

....forms of dependencies in programs. If the compiler can identify the type or the absence of dependencies it may then be possible to partition a program into independent pieces which can be executed separately. Most of this work has focused on array dependencies but Hummel, Hendern and Nicolau [HH N92] have examined the problem in the context of arbitrary (pointer based) C data structures. In these structures, dependencies due to sharing (the term used here is aliasing) can preclude parallelization. The scheme used by HH N is in effect the dual of Glide shape predicates. HH N define a language ....

J. Hummel, L. Hendren, A. Nicolau. A language for conveying the aliasing properties of dynamic, pointer-based data structures. International Conference on Parallel Processing 1992.

....is the main target may result in a power overhead which is prohibitive in embedded systems, that are typically power constrained. Instead of using such dynamic prediction mechanisms, we statically target the local memory architecture to the data access patterns. On a related front, Hummel et al. [8] address the problem of memory disambiguation in the presence of dynamic data structures to improve the parallelization opportunities. Instead of using this information for memory disambiguation, we use a similar type of closed form description generated by standard compiler analysis to represent ....

J. Hummel, L Hendren, and A Nicolau. A language for conveying the aliasing properties of dynamic, pointer-based data structures. In Proceedings of the 8th International Parallel Processing Symposium, 1994.

.... di erent data structures that have similar C declarations (for example, a binary tree and a doubly linked list both have two pointer elds, but they have very di erent properties) We have generalized our approach with the development of a dependence tester based on a theorem proving approach[HHN94] With this approach, the programmer provides a description of the data structures with ADDS, or via a lower level notation based on properties of the data structure as denoted by axioms over regular expressions. These data structure properties are combined with a traversal path analysis to ....

Joseph Hummel, Laurie J. Hendren, and Alexandru Nicolau. A language for conveying the aliasing properties of dynamic, pointer-based data structures. In Proc. of the 8th Intl. Parallel Processing Symp., pages 208-216, Cancun, Mexico, Apr. 1994. IEEE Comp. Soc.

....a DAG, which they do. Though exceedingly simple in nature, a set of aliasing axioms is able to describe quite complicated data structures, such as sparse matrices (see Section 5) and two dimensional range trees (a leaf linked tree of leaflinked trees, used in computational geometry [PS85] See [HHN94] for a more complete discussion. 3.2 Supporting Framework As pictured in Figure 2 (and discussed in Section 2.2) an accurate dependence test for PDSDP requires two types of information: information about the data structure, and information about the referenced memory locations. In the case of ....

J. Hummel, L. Hendren, and A. Nicolau. A language for conveying the aliasing properties of dynamic, pointer-based data structures. In Proceedings of the 8th International Parallel Processing Symposium, April 1994.

....E and M nodes are distinct, and (2) the data structure is acyclic. This is extremely difficult to deduce automatically, and yet is known to the programmer as a consequence of the algorithm. These properties can however be conveyed to the compiler using a combination of the approaches discussed in [11, 13], as shown in Figure 4a. The data structure has two dimensions, N and E, which denote traversal along the nodes and traversal along edges to the destination nodes, respectively. These fields are acyclic, which is conveyed by the forward keyword. The where clause supplies an axiom based on regular ....

....brevity we will focus here on source level unrolling the issues involved for refining the hierarchy at the instruction level are essentially the same, but require a bit more terminology to describe. 10 Recall that we already know that ctrl is independent of any value that node might have. [13] to state that the sets of nodes are distinct: the set of nodes S reachable by traversing next (0 or more times) is disjoint from the set of nodes reached by starting from those in S and traversing along dest[i] exactly once. Figure 4b is the main computational loop taken from the simulation ....

J. Hummel, L. Hendren, and A. Nicolau. A language for conveying the aliasing properties of dynamic, pointer-based data structures. In IPPS, 1994.

No context found.

Joseph Hummel, Laurie J. Hendren, and Alexandru Nicolau. A language for conveying the aliasing properties of dynamic, pointer-based data structures. In Proc. 8th International Parallel Processing Symposium, Cancun, Mexico, April 26-29 1994.

Online articles have much greater impact   More about CiteSeer.IST   Add search form to your site   Submit documents   Feedback  

CiteSeer.IST - Copyright Penn State and NEC