The problem of compiler optimization of sparse codes is well known and no satisfactory solutions have been found yet. One of the major obstacles is formed by the fact that sparse programs deal explicitly with the part...
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In numerical simulations of fluid-dynamics problems, solution-adaptive methods have proven to be very powerful. The implementation of the modified Shepard’s interpolation to the structured grids used in CFD is sugges...
The notion of a "proof of knowledge," suggested by Gold- wasser, Micali and Rackoff, has been used in many works as a tool for the construction of cryptographic protocols and other schemes. Yet the commonly ...
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Regular data dependence checking on sparse codes usually results in very conservative estimates of actual dependences that will occur at run-time. Clearly, this is caused by the usage of compact data structures that a...
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Regular data dependence checking on sparse codes usually results in very conservative estimates of actual dependences that will occur at run-time. Clearly, this is caused by the usage of compact data structures that are necessary to exploit sparsity in order to reduce storage requirements and computational time. However, if the compiler is presented with dense code and automatically converts it into code that operates on sparse data structures, then the dependence information obtained by analysis on the original code can be used to exploit potential concurrency in the generated code. The authors present synchronization generating and manipulating techniques that are based on this concept.
In this paper, we present a comparative performance evaluation of hot spot effects on the MIN-based and HR-based shared-memory architectures. Analytical models are described for understanding network differences and f...
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In this paper, we present a comparative performance evaluation of hot spot effects on the MIN-based and HR-based shared-memory architectures. Analytical models are described for understanding network differences and for evaluating hot spot performance on both architectures. The analytical comparisons indicate that HR-based architectures have the potential to handle various contentions caused by hot spots more efficiently than MIN-based architectures. Although there is no analytical and experimental evidence that the tree saturation phenomenon occurs in non-blocking MIN architectures, remote accesses to both hot and cool memory modules are considerably slowed down, and overall performance is significantly degraded. Intensive performance measurements on hot spots have been conducted on the BBN TC2000 (MIN-based) and the KSR1 (HR-based) machines. performance experiments were also conducted on the practical experience of hot spots with respect to synchronization lock and barrier algorithms. The experimental results support the analytical models, and present practical observations and an evaluation of hot spots on the two types of architectures.< >
We have proposed a new architecture called Axon that meets the challenges of delivering high network bandwidth directly to applications. Its novel aspects include: an integrated design of host and network interface ha...
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We have proposed a new architecture called Axon that meets the challenges of delivering high network bandwidth directly to applications. Its novel aspects include: an integrated design of host and network interface hardware, operating systems, and communication protocols; the proper division of hardware and software function; reorganisation of end-to-end protocols to take advantage of the increased functionality of the emerging high speed internetworks; and a pipelined interface between the network and host memory with no packet *** pipelined network interface performs critical per packet processing in hardware as packets flow through the pipeline, without imposing any store-and-forward buffering of packets. This requires the design of error and flow control mechanisms to be simple enough for implementation in the network interface hardware, while providing the functionality required by *** paper describes the design of the host-network interface, and, in particular, the hardware design of the critical per packet processing with emphasis on error and flow control. An extensive simulation model of the network interface hardware has been used to determine the feasibility and performance of hardware implementation of these functions.
A heuristic algorithm is presented for efficiently embedding a virtual hypercube into an irregular wavelength division multiplexing (WDM) network so that the message propagation delay is minimized. Embedding a hypercu...
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A heuristic algorithm is presented for efficiently embedding a virtual hypercube into an irregular wavelength division multiplexing (WDM) network so that the message propagation delay is minimized. Embedding a hypercube allows the communications of the many hypercube-base algorithms to map directly to the virtual network. The authors' algorithm optimizes the embedding by effective assignment of virtual addresses as well as the efficient routing of virtual connections. The three-step approach is first based on embedding the irregular graph in a hypercube so that the number of virtual edges that correspond to physical edges is minimized. The routing of the virtual connections and their assignment to logical channels is performed while minimizing the number of wavelengths that must be supported by the WDM system. Experiments with the proposed algorithm show it to produce embeddings with significantly shorter path lengths and requiring fewer wavelengths than previous methods for practical networks.
DASPK solves large-scale systems of differential-algebraic equations. We have developed two parallel versions of DASPK. They are DASPKF90, a Fortran 90 data parallel implementation for the cmf compiler, and DASPKMP, a...
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The artificial intelligence (AI) languages of logic programming and deductive databases are simple, powerful tools for genomic research. Their simplicity and power in solving the restriction mapping problem for probed...
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The artificial intelligence (AI) languages of logic programming and deductive databases are simple, powerful tools for genomic research. Their simplicity and power in solving the restriction mapping problem for probed partial experiments are demonstrated, and the more traditional Prolog language is compared with the newer logical data language (LDL). The comparisons are made with respect to procedural control, declarativeness, ease of code modification, and efficiency. While a Prolog program means logic plus control, an LDL program means logic plus little control because its compiler takes care of most of the control problem. While Prolog works top-down and is more efficient, LDL works bottom-up and is easier to use.< >
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