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193
Automatic Translation of FORTRAN Programs to Vector Form
 ACM Transactions on Programming Languages and Systems
, 1987
"... This paper discusses the theoretical concepts underlying a project at Rice University to develop an automatic translator, called PFC (for Parallel FORTRAN Converter), from FORTRAN to FORTRAN 8x. The Rice project, based initially upon the research of Kuck and others at the University of Illinois [6, ..."
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Cited by 294 (32 self)
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This paper discusses the theoretical concepts underlying a project at Rice University to develop an automatic translator, called PFC (for Parallel FORTRAN Converter), from FORTRAN to FORTRAN 8x. The Rice project, based initially upon the research of Kuck and others at the University of Illinois [6, 1721, 24, 32, 36], is a continuation of work begun while on leave at IBM Research in Yorktown Heights, N.Y. Our first implementation was based on the Illinois PARAFRASE compiler [20, 36], but the current version is a completely new program (although it performs many of the same transformations as PARAFRASE). Other projects that have influenced our work are the Texas Instruments ASC compiler [9, 33], the Cray1 FORTRAN compiler [15], and the Massachusetts Computer Associates Vectorizer [22, 25]. The paper is organized into seven sections. Section 2 introduces FORTRAN 8x and gives examples of its use. Section 3 presents an overview of the translation process along with an extended translation example. Section 4 develops the concept of interstatement dependence and shows how it can be applied to the problem of vectorization. Loop carried dependence and loop independent dependence are introduced in this section to extend dependence to multiple statements and multiple loops. Section 5 develops dependencebased algorithms for code generation and transformations for enhancing the parallelism of a statement. Section 6 describes a method for extending the power of data dependence to control statements by the process of IF conversion. Finally, Section 7 details the current state of PFC and our plans for its continued development
Optimally Profiling and Tracing Programs
 ACM Transactions on Programming Languages and Systems
, 1994
"... copies of part or all of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for components of this work owned by others ..."
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Cited by 279 (19 self)
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copies of part or all of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for components of this work owned by others than ACM must be honored. Abstracting with credit is permitted. To copy otherwise, to republish, to post on servers, or to redistribute to lists, requires prior specific permission and/or a fee. Request permissions from Publications
Anomalous payloadbased network intrusion detection
, 2004
"... We present a payloadbased anomaly detector, we call PAYL, for intrusion detection. PAYL models the normal application payload of network traffic in a fully automatic, unsupervised fashion. The method we choose is very efficient; our goal is to deploy the detector in high bandwidth environments eith ..."
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Cited by 200 (12 self)
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We present a payloadbased anomaly detector, we call PAYL, for intrusion detection. PAYL models the normal application payload of network traffic in a fully automatic, unsupervised fashion. The method we choose is very efficient; our goal is to deploy the detector in high bandwidth environments either on a firewall, a network appliance, a proxy server or on the target hosts. We first compute during a training phase a profile byte frequency distribution and their standard deviation of the application payload flowing to a single host and port. We then use Mahalanobis distance during the detection phase to calculate the similarity of new data against the precomputed profile. The detector compares this measure against a threshold and generates an alert when the distance of the new input exceeds this threshold. The model is host and portspecific and is conditioned on the payload length. Thus, a set of profiles are computed for every possible length payload. A second phase clusters the profiles to increase accuracy and decrease resource consumption. The method has the advantage of being very fast to compute, is stateless and does not parse the input stream, generates a small model, and can be easily modified to an incremental online learning algorithm so that the model is continuously updated to maintain an accurate normal model in realtime. The modeling method is completely unsupervised, and is tolerant to noise in the training data. Furthermore, the method is also resistant to mimicryattack; attackers would need to model the site’s normal payload distributions in order to pad their poisoned payload to go unnoticed by the
A fast algorithm for finding dominators in a flowgraph
 ACM Transactions on Programming Languages and Systems
, 1979
"... A fast algoritbm for finding dominators in a flowgraph is presented. The algorithm uses depthfirst search and an efficient method of computing functions defined on paths in trees. A simple implementation of the algorithm runs in O(m log n) time, where m is the number of edges and n is the number o ..."
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Cited by 144 (3 self)
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A fast algoritbm for finding dominators in a flowgraph is presented. The algorithm uses depthfirst search and an efficient method of computing functions defined on paths in trees. A simple implementation of the algorithm runs in O(m log n) time, where m is the number of edges and n is the number of vertices in the problem graph. A more sophisticated implementation runs in O(ma(m, n)) time, where a(m, n) is a functional inverse of Ackermann's function. Both versions of the algorithm were implemented in Algol W, a Stanford University version of Algol, and tested on an IBM 370/168. The programs were compared with an implementation by Purdom and Moore of a straightforward O(mn)time algorithm, and with ~a bit vector algorithm described by Aho and Ullman. The fast algorithm beat the straightforward algorithm and the bit vector algorithm on all but the smallest graphs tested.
Optimal Priority Assignment And Feasibility Of Static Priority Tasks With Arbitrary Start Times
, 1991
"... Within the hard realtime community, static priority preemptive scheduling is receiving increased attention. Current optimal priority assignment schemes require that at some point in the system lifetime all tasks must be released simultaneously. Two main optimal priority assignment schemes have bee ..."
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Cited by 94 (2 self)
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Within the hard realtime community, static priority preemptive scheduling is receiving increased attention. Current optimal priority assignment schemes require that at some point in the system lifetime all tasks must be released simultaneously. Two main optimal priority assignment schemes have been proposed: ratemonotonic, where task period equals deadline, and deadlinemonotonic where task deadline maybe less than period. When tasks are permitted to have arbitrary start times, a common release time between all tasks in a task set may not occur. In this eventuality, both ratemonotonic and deadlinemonotonic priority assignments cease to be optimal. This paper presents an method of determining if the tasks with arbitrary release times will ever share a common release time. This has complexity O(m log e m) in the longest task period. Also, an optimal priority assignment method is given, of complexity O(n 2 + n) in the number of tasks. Finally, an efficient feasibility test is presen...
Incremental contextdependent analysis for languagebased editors
 ACM Transactions on Programming Languages and Systems
, 1983
"... Knowledge of a programming language's grammar allows languagebased editors to enforce syntactic correctness at all times during development by restricting editing operations to legitimate modifications ot ~ the program's contextfree derivation tree; however, not all language constraints can be enf ..."
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Cited by 81 (10 self)
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Knowledge of a programming language's grammar allows languagebased editors to enforce syntactic correctness at all times during development by restricting editing operations to legitimate modifications ot ~ the program's contextfree derivation tree; however, not all language constraints can be enforced in this way because not all features can be described by the contextfree formalism. Attribute grammars permit contextdependent language features to be expressed in a modular, declarative fashion and thus are a good basis for specifying languagebased editors. Such editors represent programs as attributed trees, Which are modified by operations such as subtree pruning and grafting. Incremental analysis is performed by updating attribute values after every modification. This paper discusses how updating can be carried out and presents several algorithms for the task, including one that is asymptotically optimal in time.
Generalized pattern avoidance
 European J. Combin
"... Abstract. Recently, Babson and Steingrímsson have introduced generalised permutation patterns that allow the requirement that two adjacent letters in a pattern must be adjacent in the permutation. We will consider pattern avoidance for such patterns, and give a complete solution for the number of pe ..."
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Cited by 74 (5 self)
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Abstract. Recently, Babson and Steingrímsson have introduced generalised permutation patterns that allow the requirement that two adjacent letters in a pattern must be adjacent in the permutation. We will consider pattern avoidance for such patterns, and give a complete solution for the number of permutations avoiding any single pattern of length three with exactly one adjacent pair of letters. For eight of these twelve patterns the answer is given by the Bell numbers. For the remaining four the answer is given by the Catalan numbers. We also give some results for the number of permutations avoiding two different patterns. These results relate the permutations in question to Motzkin paths, involutions and nonoverlapping partitions. Furthermore, we define a new class of set partitions, called monotone partitions, and show that these partitions are in onetoone correspondence with nonoverlapping partitions. 1.
Generating Functions for Generating Trees
 PROCEEDINGS OF 11TH FORMAL POWER SERIES AND ALGEBRAIC COMBINATORICS
, 1999
"... Certain families of combinatorial objects admit recursive descriptions in terms of generating trees: each node of the tree corresponds to an object, and the branch leading to the node encodes the choices made in the construction of the object. Generating trees lead to a fast computation of enumerati ..."
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Cited by 68 (18 self)
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Certain families of combinatorial objects admit recursive descriptions in terms of generating trees: each node of the tree corresponds to an object, and the branch leading to the node encodes the choices made in the construction of the object. Generating trees lead to a fast computation of enumeration sequences (sometimes, to explicit formulae as well) and provide efficient random generation algorithms. We investigate the links between the structural properties of the rewriting rules defining such trees and the rationality, algebraicity, or transcendence of the corresponding generating function.