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Do while loop

About: Do while loop is a research topic. Over the lifetime, 263 publications have been published within this topic receiving 6144 citations.


Papers
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Journal ArticleDOI
Leslie Lamport1
TL;DR: Methods are developed for the parallel execution of different iterations of a DO loop and practical application to the design of compilers for such computers is discussed.
Abstract: Methods are developed for the parallel execution of different iterations of a DO loop. Both asynchronous multiprocessor computers and array computers are considered. Practical application to the design of compilers for such computers is discussed.

678 citations

Proceedings ArticleDOI
B. Moore1
01 Dec 1975
TL;DR: In this article, a characterization of all closed loop eigenvector sets which can be obtained with a given set of distinct closed-loop eigenvalues using state feedback is given.
Abstract: A characterization is given for the class of all closed loop eigenvector sets which can be obtained with a given set of distinct closed loop eigenvalues using state feedback. It is shown, furthermore, that the freedom one has in addition to specifying the closed loop eigenvalues is precisely this: to choose one set of closed loop eigenvectors from this class. Included in the proof of this result is an algorithm for computing the matrix of feedback gains which gives the chosen closed loop eigenvalues and eigenvectors. A design scheme based on these results is presented which gives the designer considerable freedom to choose the distribution of the modes among the output components. One interesting feature is that the distribution of a mode among the output components can be varied even if the mode is not controllable.

583 citations

Journal ArticleDOI
TL;DR: The authors study run-time methods to automatically parallelize and schedule iterations of a do loop in certain cases where compile-time information is inadequate and present performance results from experiments conducted on the Encore Multimax, illustrating that run- time reordering of loop indexes can have a significant impact on performance.
Abstract: The authors study run-time methods to automatically parallelize and schedule iterations of a do loop in certain cases where compile-time information is inadequate. The methods presented involve execution time preprocessing of the loop. At compile-time, these methods set up the framework for performing a loop dependency analysis. At run-time, wavefronts of concurrently executable loop iterations are identified. Using this wavefront information, loop iterations are reordered for increased parallelism. The authors utilize symbolic transformation rules to produce: inspector procedures that perform execution time preprocessing, and executors or transformed versions of source code loop structures. These transformed loop structures carry out the calculations planned in the inspector procedures. The authors present performance results from experiments conducted on the Encore Multimax. These results illustrate that run-time reordering of loop indexes can have a significant impact on performance. >

256 citations

Book
01 Jan 1993
TL;DR: This book provides the general mathematical background needed for loop transformations (including those basic mathematical algorithms), discusses data dependence, and introduces the major transformations.
Abstract: Automatic transformation of a sequential program into a parallel form is a subject that presents a great intellectual challenge and promises great practical rewards. There is a tremendous investment in existing sequential programs, and scientists and engineers continue to write their application programs in sequential languages (primarily in Fortran),but the demand for increasing speed is constant. The job of a restructuring compiler is to discover the dependence structure of a given program and transform the program in a way that is consistent with both that dependence structure and the characteristics of the given machine. Much attention in this field of research has been focused on the Fortran do loop. This is where one expects to find major chunks of computation that need to be performed repeatedly for different values of the index variable. Many loop transformations have been designed over the years, and several of them can be found in any parallelizing compiler currently in use in industry or at a university research facility. Loop Transformations for Restructuring Compilers: The Foundations provides a rigorous theory of loop transformations. The transformations are developed in a consistent mathematical framework using objects like directed graphs, matrices and linear equations. The algorithms that implement the transformations can then be precisely described in terms of certain abstract mathematical algorithms. The book provides the general mathematical background needed for loop transformations (including those basic mathematical algorithms), discusses data dependence, and introduces the major transformations. The next volume will build a detailed theory of loop transformations based on the material developed here. Loop Transformations for Restructuring Compilers: The Foundations presents a theory of loop transformations that is rigorous and yet reader-friendly.

253 citations

Proceedings ArticleDOI
01 Jan 1967
TL;DR: A class of programs, called “Loop programs,” which consists only of assignment statements and iteration (loop) statements, the latter resembling the DO statement of FORTRAN, and special cases of the FOR and THROUGH statements of ALGOL and MAD.
Abstract: Anyone familiar with the theory of computability will be aware that practical conclusions from the theory must be drawn with caution. If a problem can theoretically be solved by computation, this does not mean that it is practical to do so. Conversely, if a problem is formally undecidable, this does not mean that the subcases of primary interest are impervious to solution by algorithmic methods.In the next section we describe such a class of programs, called “Loop programs.” Each Loop program consists only of assignment statements and iteration (loop) statements, the latter resembling the DO statement of FORTRAN, and special cases of the FOR and THROUGH statements of ALGOL and MAD. The bound on the running time of a Loop program is determined essentially by the length of the program and the depth of nesting of its loops.

184 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20191
20182
20171
20164
20159
20149