Robert Cypher

Learn More
This paper presents a deterministic sorting algorithm, called Sharesort, that sorts n records on an n processor hypercube, shuffle-exchange or cube-connected cycles in O(log n(loglog n) 2) time in the worst case. The algorithm requires only a constant amount of storage at each processor. The fastest previous deterministic algorithm for this problem was(More)
A collective communication library for parallel computers includes frequently used operations such as broadcast, reduce, scatter, gather, concatenate, synchronize, and shift. Such a library provides users with a convenient programming interface, efficient communication operations, and the advantage of portability. A library of this nature, the Collective(More)
This paper studies the behavior of scientific applications running on distributed memory parallel computers. Our goal is to quantify the floating point, memory, I/O and communication requirements of highly parallel scientific applications that perform explicit communication. In addition to quantifying these requirements for fixed problem sizes and numbers(More)
Many parallel computers consist of processors connected in the form of a d-dimensional mesh or hypercube. Twoand three-dimensional meshes have been shown to be efficient in manipulating images and dense matrices, whereas hypercubes have been shown to be well suited to divide-andconquer algorithms requiring global communication. However, even a single faulty(More)
This paper examines the amount of communication that is required for performing mutual exclusion. It is assumed that n processors communicate via accesses to a shared memory that is physically distributed among the processors. We consider the possibility of creating a scalable mutual exclusion protocol that requires only a constant amount of communication(More)
This paper presents a formal model ofthe pin requirements of a parallel computer. This model is then used to obtain bounds on the pin requirements of different parallel machines and on the tradeoffs between pins and time. Specifically, two new bounds are established on the relationship between pin requirements and the time needed to sort or permute data.(More)