The phase ordering of register allocation and instruction scheduling in a compiler and their integration have been well studied for in-order issue and VLIW processors. In this paper we study this problem in the contex...
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The phase ordering of register allocation and instruction scheduling in a compiler and their integration have been well studied for in-order issue and VLIW processors. In this paper we study this problem in the context of out-of-order issue processors. Such a study is interesting as the dynamic instruction ordering and register renaming support mechanisms in out-of-order issue processors are similar in spirit to what the complex register allocation and instruction scheduling techniques do at compile-time. We evaluated four existing techniques, namely postpass scheduling, prepass scheduling, parallel interference graph, and integrated prepass scheduling methods. Our initial experimental results reveal that for o-o-o issue processors the focus should be on reducing the register pressure/spill code than exposing the parallelism at compiling time.
This paper describes a specification-based regression testing technique that can be applied for revalidating concurrent programs after specification changes. This kind of regression testing technique requires sequenci...
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This paper describes a specification-based regression testing technique that can be applied for revalidating concurrent programs after specification changes. This kind of regression testing technique requires sequencing constraints which specify the precedence relations among synchronization events. In our method, the sequencing constraints are extracted automatically from Message Sequence Charts (MSCs) that are considered to be partial and nondeterministic specifications. We show how to identify the sequencing constraints affected by the modifications of a specification rather than creating new sequencing constraints from scratch to reduce the cost of regression testing. We also describe how to determine whether the affected sequencing constraints are satisfied by the program being tested.
Traditional character extraction methods use split-and-merge or color segmentation methods from the whole image. These methods do not reflect characteristics of characters such that character regions can be extracted ...
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ISBN:
(纸本)0780354060
Traditional character extraction methods use split-and-merge or color segmentation methods from the whole image. These methods do not reflect characteristics of characters such that character regions can be extracted incorrectly. In this paper, we use topographical features of characters to extract the character points and use the density of those points to extract the candidate regions for captions. Character regions are determined by testing several conditions and verifying those candidate regions. Experimental results show that the candidate region extraction rate is 100%, and the character region extraction rate is 99%. Non-character regions can exist within the extracted character regions which are removed using the Isodata color clustering method.
The Hybrid technology Multi-Threading project is a long-term study of the feasibility of combining several emerging technologies to reach 1 petaFLOPS within ten years. HTMT will combine high-speed superconductor proce...
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The Hybrid technology Multi-Threading project is a long-term study of the feasibility of combining several emerging technologies to reach 1 petaFLOPS within ten years. HTMT will combine high-speed superconductor processors, semiconductor memories with built-in processors, high-speed optical interconnects, and high-density holographic storage. While there are major challenges in all aspects of this project, those in processor architecture are the focus of this paper. Fundamental differences between RSFQ circuits and conventional semiconductor circuits, including a radical jump in clock speed, make today's processor design approaches inappropriate for HTMT. Sequential instruction dispatching, even within the lowest programming unit (a strand), will lead to unacceptably high latencies, hence poor performance. We propose alternative processor designs which use fine-grain synchronizations between individual instructions in order to avoid these bottlenecks.
A new method for version controlling of a tree structure is presented. The key feature of the method is that the latest state of a tree is retained and other versions are constructed from it on request, and informatio...
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Handling the procedure interface in an HPF compiler is complex due to the many possible combinations of Fortran 90/HPF properties of an actual array argument and its associated dummy argument. This paper describes an ...
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As gradually increasing the complexity of the software, it is very important to improve the quality and the development productivity using the software reuse techniques. From the existing reuse research about function...
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A prototype of an environmental simulation and monitoring system for urban areas has been developed. This system provides state-of-the-art air and water pollution calculation and analysis tools. A distributed client-s...
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A prototype of an environmental simulation and monitoring system for urban areas has been developed. This system provides state-of-the-art air and water pollution calculation and analysis tools. A distributed client-server architecture based on the Internet has been chosen to allow authorities to run large models requiring HPC hardware on remote model servers. The main focus of this paper is the description of a model designed for the computation of the extra ozone production in urban areas and for short-term ozone forecast purposes. Within the framework of an integrated simulation and monitoring system, this model benefits from the easy exchange of modeled and monitored data. Automatic interfaces to monitoring nets allow an operational use of the model.
HITERM is a decision support tool for the management of the accidental release of toxic substances. It consists of several interconnected (possibly remotely located) parts. The main server supervises the actions of th...
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HITERM is a decision support tool for the management of the accidental release of toxic substances. It consists of several interconnected (possibly remotely located) parts. The main server supervises the actions of the system. It contains a graphical user interface (GUI), including a geographical information system (GIS) and other databases. It is connected to mobile clients at the place of the accident to collect data and to inform about the situation and the recommended actions. On the other hand, the main server can start a model server to perform simulation of the pollution evolution. Decision support tools provide guidance to the user for the management of an evolving emergency situation. The underlying simulation system for the air domain is discussed in more detail and results of a simulation of a traffic accident in the Reuss Valley in Switzerland are shown.
This paper presents a modeling approach based on deterministic and stochastic Petri nets (DSPN) for analyzing the performance of node architectures for MIMD multiprocessor systems with distributed memory. DSPN are a n...
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This paper presents a modeling approach based on deterministic and stochastic Petri nets (DSPN) for analyzing the performance of node architectures for MIMD multiprocessor systems with distributed memory. DSPN are a numerically solvable modeling formalism with a graphical representation. The modeling approach supports design decisions for node architectures by providing quantitative results concerning processor and memory utilization for several design alternatives. To illustrate the proposed approach, DSPN of two node architectures are presented and employed for a comparative performance study.
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