Thomas J. Sheffler

A Graph Separator Theorem and Its Application to Gaussian Elimination to Optimize Boolean Expressions for Parallel Evaluation. (1998)

Sheffler, Thomas J.

Gaussian elimination, which has been shown to be applicable to the solution problems in many different domains, is the technique used by COSMOS to symbolically analyze digital MOS networks for their...

Work Efficient Hashing on Parallel and Vector Computers, (1998)

Sheffler, Thomas J., Bryant, Randal E.

Hashing techniques have long been used to efficiently store and locate data indexed by key. Recently, parallel hashing algorithms have been developed that allow table insertion of many keys in a few...

Implementing the Multiprefix Operation on Parallel and Vector Computers. (1998)

Sheffler, Thomas J.

For an ordered set of n values, each with an associated integer label, the multiprefix operation calculates a partial sum for each value that is the sum of all preceding values with the same label....

Match and Move, an Approach to Data Parallel Computing. (1998)

Sheffler, Thomas J.

The match operation, introduced by G. Sabot, is a parallel primitive describing a communication pattern. For two vectors of keys, called the 'source' and 'destination,' a path is indicated for each...

Direct all correspondence to: (1996)

Siddhartha Chatterjee, John R. Gilbert, Leonid Oliker, Robert Schreiber, Thomas J. Sheffler, Siddhartha Chatterjee, ...

*This work was performed while Chatterjee and Sheffier were postdoctoral scientists at RIACS, and Schreiber was a senior scientist at R1ACS. This work was supported by the NAS Systems Division via...

Algorithms for Automatic Alignment of Arrays (1996)

Siddhartha Chatterjee, John R. Gilbert, Leonid Oliker, Robert Schreiber, Thomas J. Sheffler, Prof Siddhartha Chatterjee

Aggregate data objects (such as arrays) are distributed across the processor memories when compiling a data-parallel language for a distributed-memory machine. The mapping determines the amount of...

An object-oriented approach to nested data parallelism (1995)

Thomas J. Sheffler, Thomas J. Sheffler, Siddhartha Chatterjee, Siddhartha Chatterjee

This paper describes an implementation technique for integrating nested data parallelism into an object-oriented language. Data-parallel programming employs sets of data called "collections...

Aligning parallel arrays to reduce communication (1995)

Thomas J. Sheffler, Robert Schreiber, John R. Gilbert, Siddhartha Chatterjee, Thomas J. Sheffler, Robert Schreiber, ...

Axis and stride alignment is an important optimization in compiling data-parallel programs for distributed-memory machines. We previously developed an optimal algorithm for aligning array...

An Object-Oriented Approach to Nested Data Parallelism (1995)

Thomas J. Sheffler, Siddhartha Chatterjee

This paper describes an implementation technique for integrating nested data parallelism into an object-oriented language. Data-parallel programming employs data aggregates called...

An Object-Oriented Approach to Nested Data Parallelism (1995)

Thomas J. Sheffler, Siddhartha Chatterjee

This paper describes an implementation technique for integrating nested data parallelism into an object-oriented language. Data-parallel programming employs sets of data called...

Efficient Distribution Analysis via Graph Contraction (1995)

Thomas J. Sheffler, Robert Schreiber, William Pugh, John R. Gilbert, Siddhartha Chatterjee

Alignment and distribution of data by an optimizing compiler is a dream of both manufacturers and users of parallel computers. The distribution problem has been formulated as an NP-complete graph...

A portable MPI-based parallel vector template library (1995)

Thomas J. Sheffler

This paper discusses the design and implementation of a polymorphic collection library for distributed address-space parallel computers. The library provides a data-parallel programming model for C++...

Aligning Parallel Arrays to Reduce Communication (1995)

Thomas J. Sheffler, Robert Schreiber, John R. Gilbert, Siddhartha Chatterjee

Axis and stride alignment is an important optimization in compiling data-parallel programs for distributed-memory machines. We previously developed an optimal algorithm for aligning array...

Array distribution in data-parallel programs (1994)

Siddhartha Chatterjee, John R. Gilbert, Robert Schreiber, Thomas J. Shefl:ler, Siddhartha Chatterjee, John R. Gilbert, ...

We consider dism_oution at compile time of the array data in a distributed-memory implementation of a data-parallel program written in a language like Fortran 90. We allow dynamic redistribution of...

Array distribution in data-parallel programs (1994)

Siddhartha Chatterjee, John R. Gilbert, Robert Schreiber, Thomas J. Sheffler, Siddhartha Chatterjee, John R. Gilbert, ...

We consider distribution at compile time of the array data in a distributed-memory implementation of a data-parallel program written m a language like Fortran 90. We allow dynamic redistribution of...

Modeling Data-Parallel Programs with the Alignment-Distribution Graph (1994)

Siddhartha Chatterjee, John R. Gilbert, Robert Schreiber, Thomas J. Sheffler

We present an intermediate representation of a program called the Alignment-Distribution Graph that exposes the communication requirements of the program. The representation exploits ideas developed...

Array Distribution in Data-Parallel Programs (1994)

Siddhartha Chatterjee, John R. Gilbert, Robert Schreiber, Thomas J. Sheffler

We consider distribution at compile time of the array data in a distributed-memory implementation of a dataparallel program written in a language like Fortran 90. We allow dynamic redistribution of...

Nested dissection: A survey and comparison of various nested dissection algorithms (1992)

Manpreet S. Khaira, Gary L. Miller, Thomas J. Sheffler

Methods for solving sparse linear systems of equations can be categorized under two broad classes- direct and iterative. Direct methods are methods based on gaussian elimination. This report...

Nested Dissection: A survey and comparison of various nested dissection algorithms (1992)

Manpreet S. Khaira, Gary L. Miller, Thomas J. Sheffler

Methods for solving sparse linear systems of equations can be categorized under two broad classes - direct and iterative. Direct methods are methods based on gaussian elimination. This report...

Nested Dissection: A survey and comparison of various (1992)

Nested Dissection Algorithms, Manpreet S. Khaira, Gary L. Miller, Thomas J. Sheffler

and iterative. Direct methods are methods based on gaussian elimination. This report discusses one such direct method namely Nested dissection. Nested Dissection, originally proposed by Alan George,...