The emerging hardware support for thread-level speculation opens new opportunities to parallelize sequential programs beyond the traditional limits. By speculating that many data dependences are unlikely during runtim...
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The emerging hardware support for thread-level speculation opens new opportunities to parallelize sequential programs beyond the traditional limits. By speculating that many data dependences are unlikely during runtime, consecutive iterations of a sequential loop can be executed speculatively in parallel. Runtime parallelism is obtained when the speculation is correct. To take full advantage of this new execution model, a program needs to be programmed or compiled in such a way that it exhibits high degree of speculative thread-level parallelism. We propose a comprehensive cost-driven compilation framework to perform speculative parallelization. Based on a misspeculation cost model, the compiler aggressively transforms loops into optimal speculative parallel loops and selects only those loops whose speculative parallel execution is likely to improve program performance. The framework also supports and uses enabling techniques such as loop unrolling, software value prediction and dependence profiling to expose more speculative parallelism. The proposed framework was implemented on the ORC compiler. Our evaluation showed that the cost-driven speculative parallelization was effective. Our compiler was able to generate good speculative parallel loops in ten Spec2000Int benchmarks, which currently achieve an average 8% speedup. We anticipate an average 15.6% speedup when all enabling techniques are in place.
We introduce a first-order language for semantic underspecification that we call Constraint Language for Lambda-Structures (CLLS). A λ-structure can be considered as a λ-term up to consistent renaming of bound varia...
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Multiagent systems have been proposed in the literature as a suitable architectural and implementation approach for cross-enterprise collaboration, due to their support for decentral decision-making and peer-to-peer c...
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ISBN:
(纸本)9783540790426
Multiagent systems have been proposed in the literature as a suitable architectural and implementation approach for cross-enterprise collaboration, due to their support for decentral decision-making and peer-to-peer coordination, loosely coupled interaction, modeling support for the notion of electronic institutions, and built-in adaptability mechanisms. While we agree with this general view, we argue that different application domain and different market constellations require different types of architecture. In this paper we look at the specific problem of selecting an information and communication technology (ICT) architecture for cross-enterprise business process (CBP) design and enactment. Therefore we identify three important architectural patterns for CBP enactment. We then propose a decision method for architecture selection based on the analytic hierarchy process (AHP) approach. Finally we illustrate the method by applying it to two application scenarios with differing characteristics. Robustness of the decision method is analyzed by performing a sensitivity analysis.
This paper presents an approach for the automatic generation of shortest Distinguishing Sequences (DS) with the Uppaal model checker. The presented method is applicable to a large number of extended finite state machi...
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ISBN:
(纸本)1595931155
This paper presents an approach for the automatic generation of shortest Distinguishing Sequences (DS) with the Uppaal model checker. The presented method is applicable to a large number of extended finite state machines and it will find an optimal result, if a DS sequence exists for the considered automaton. Our approach is situated in an integrated testing environment that is used to generate checking sequences. The generation method is based on a DS model, which is derived from the same test model that is used for generating test cover sets. The problem of generating DS is reduced to the definition of a DS model and for this reason the complexity of our approach depends mainly on the used model checking algorithm. This means, that the presented method is automatically improved, when the model checking algorithm is improved. This includes the generation of optimal DS depending on the ability of the model checker to produce optimal results. Copyright 2005 ACM.
In this paper, we leverage service-orientation as a means for combining the strengths of the UML-based code generator framework AndroMDA for generating static application aspects with code generators focussing on the ...
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In this paper, we leverage service-orientation as a means for combining the strengths of the UML-based code generator framework AndroMDA for generating static application aspects with code generators focussing on the dynamic aspects. The latter are developed with Genesys, a code generation framework that combines the ideas of model-driven development and service-orientation in order to enable a high-level engineering of code generators. This demonstrates a new level of reusability and even has the potential for full code generation, which elegantly eliminates the need for the typical round-trip engineering in model-driven development environments. We demonstrate the applicability of our approach by means of an example from the field of bioinformatics.
Bio-jETI is a framework for model-based, graphical design, execution and management of bioinformatics analysis processes. Formal methodology like automatic service composition extends the framework and, in particular,...
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Bio-jETI is a framework for model-based, graphical design, execution and management of bioinformatics analysis processes. Formal methodology like automatic service composition extends the framework and, in particular, allows for semantically aware workow development. In this study we apply the workow synthesis methodology to the EMBOSS suite of sequence analysis tools. As neither the tool suite itself nor its various interfaces provide ready-to-use semantic annotations, we set up a domain model that uses a high-level, semantically meaningful type nomenclature to describe the input/output behavior of the single EMBOSS tools. Based on this domain model, we demonstrate how working with the large, heterogeneous, and hence manually intractable EMBOSS collection is simplified by our service composition methodology.
A hidden Markov model (HMM) is a statistical model in which the system being modeled is assumed to be a Markov process with hidden states. This model has been widely used in speech recognition and biological sequence ...
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A hidden Markov model (HMM) is a statistical model in which the system being modeled is assumed to be a Markov process with hidden states. This model has been widely used in speech recognition and biological sequence analysis. Viterbi algorithm has been proposed to compute the most probable value of these hidden states in regards to an observed data sequence. Constrained HMM extends this framework by adding some constraints on a HMM process run. In this paper, we propose to introduce constrained HMMs into Constraint programming. We propose new version of the Viterbi algorithm for this new framework. Several constraint techniques are used to reduce the search of the most probable value of hidden states of a constrained HMM. An implementation based on PRISM, a logic programming language for statistical modeling, is presented.
This book constitutes the refereed proceedings of the International Conference on Multiscore Software Engineering, Performance, and Tools, MSEPT 2012, held in Prague in May/June 2012. The 9 revised papers, 4 of which ...
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ISBN:
(数字)9783642312021
ISBN:
(纸本)9783642312014
This book constitutes the refereed proceedings of the International Conference on Multiscore Software Engineering, Performance, and Tools, MSEPT 2012, held in Prague in May/June 2012. The 9 revised papers, 4 of which are short papers were carefully reviewed and selected from 24 submissions. The papers address new work on optimization of multicore software, program analysis, and automatic parallelization. They also provide new perspectives on programming models as well as on applications of multicore systems.
PROPHETS is our flexible framework for the synthesis of processes from libraries of basic services. In this paper we demonstrate how its synthesis strategy can be tailored to the considered application domain. For thi...
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PROPHETS is our flexible framework for the synthesis of processes from libraries of basic services. In this paper we demonstrate how its synthesis strategy can be tailored to the considered application domain. For this purpose, PROPHETS provides a number of configuration options, such as different data exchange formats (e.g. shared variables and pipe lining) for the resulting process, as well as structural and temporal logic constraints for minimizing the inherent search space. We illustrate the impact of adequate synthesis tailoring by contrasting two real-life case studies with diametric characteristics.
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