| 11. |
- Ekman, Torbjörn, et al.
(författare)
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Rewritable Reference Attributed Grammars
- 2004
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Ingår i: ECOOP 2004 – Object-Oriented Programming. Proceedings (Lecture Notes in Computer Science). - Berlin, Heidelberg : Springer Berlin Heidelberg. - 0302-9743 .- 1611-3349. - 9783540221593 ; 3086, s. 144-169
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Konferensbidrag (refereegranskat)abstract
- This paper presents an object-oriented technique for rewriting abstract syntax trees in order to simplify compilation. The technique, Rewritable Reference Attributed Grammars (ReRAGs), is completely declarative and supports both rewrites and computations by means of attributes. We have implemented ReRAGs in our aspect-oriented compiler compiler tool JastAdd II. Our largest application is a complete static-semantic analyzer for Java 1.4. ReRAGs uses three synergistic mechanisms for supporting separation of concerns: inheritance for model modularization, aspects for cross-cutting concerns, and rewrites that allow computations to be expressed on the most suitable model. This allows compilers to be written in a high-level declarative and modular fashion, supporting language extensibility as well as reuse of modules for different compiler-related tools. We present the ReRAG formalism, its evaluation algorithm, and examples of its use. Initial measurements using a subset of the Java class library as our benchmarks indicate that our generated compiler is only a few times slower than the standard compiler, javac, in J2SE 1.4.2 SDK. This shows that ReRAGs are already useful for large-scale practical applications, despite that optimization has not been our primary concern so far.
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| 12. |
- Ekman, Torbjörn
(författare)
-
Rewritable Reference Attributed Grammars - design, implementation, and applications
- 2004
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis presents an object-oriented technique for rewriting abstract syntax trees in order to simplify compilation. The technique, Rewritable Reference Attributed Grammars (ReRAGs), is completely declarative and supports both rewrites and computations by means of attributes. We have implemented ReRAGs in our aspect-oriented compiler compiler tool JastAdd II. We present the ReRAG formalism, its evaluation algorithm, and examples of its use. JastAdd II uses three synergistic mechanisms for supporting separation of concerns: inheritance for model modularization, aspects for cross-cutting concerns, and rewrites that allow computations to be expressed on the most suitable model. This allows compilers to be written in a high-level declarative and modular fashion, supporting language extensibility as well as reuse of modules for different compiler-related tools. Each technique is presented using a series of simplified examples from static semantic analysis for the Java programming language. A case study is presented where ReRAGs are used extensively to implement a compiler for the Control Module extension to the IEC61131-3 automation languages. That Control Modules concept is further extended, in a modular fashion, with object-oriented features to improve encapsulation, composition mechanisms, code re-use, and type safety.
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| 13. |
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| 14. |
- Falahati, Sorour, 1971, et al.
(författare)
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Adaptive Modulation Systems for Predicted Wireless Channels
- 2004
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Ingår i: IEEE Transactions on Communications. - 0090-6778 .- 1558-0857. ; 52:2, s. 307-316
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Tidskriftsartikel (refereegranskat)abstract
- When adaptive modulation is used to counter short-term fading in mobile radio channels, signaling delays create problems with outdated channel state information. The use of channel power prediction will improve the performance of the link adaptation. It is then of interest to take the quality of these predictions into account explicitly when designing an adaptive modulation scheme. We study the optimum design of an adaptive modulation scheme based on uncoded M -quadrature amplitude modulation, assisted by channel prediction for the flat Rayleigh fading channel. The data rate, and in some variants the transmit power, are adapted to maximize the spectral efficiency, subject to average power and bit-error rate constraints. The key issues studied here are how a known prediction error variance will affect the optimized transmission properties, such as the signal-to-noise ratio (SNR) boundaries that determine when to apply different modulation rates, and to what extent it affects the spectral efficiency. This investigation is performed by analytical optimization of the link adaptation, using the statistical properties of a particular, but efficient, channel power predictor. Optimum solutions for the rate and transmit power are derived, based on the predicted SNR and the prediction error variance.
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| 15. |
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| 16. |
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| 17. |
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| 18. |
- Ive, Anders, et al.
(författare)
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Garbage collector interface
- 2002
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Ingår i: Proceedings of the Tenth Nordic Workshop on Programming and Software Development Tools and Techniques (NWPER 2002).
-
Konferensbidrag (refereegranskat)abstract
- The purpose of the presented garbage collector interface is to provide a universal interface for many different implementations of garbage collectors. This is to simplify the integration and exchange of garbage collectors, but also to support incremental, non-conservative, and thread safe implementations. Due to the complexity of the interface, it is aimed at code generators and preprocessors. Experiences from ongoing implementations indicate that the garbage collector interface successfully provides the necessary functionality in an efficient way,
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| 19. |
- Nilsson, Anders, et al.
(författare)
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Deterministic Java in tiny embedded systems
- 2001
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Ingår i: Fourth IEEE International Symposium on Object-Oriented Real-Time Distributed Computing, 2001. ISORC - 2001. Proceedings.. - 0769510892 ; , s. 60-68
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Konferensbidrag (refereegranskat)abstract
- As embedded systems become more and more complex, and the time to market becomes shorter, there is a need in the embedded systems community to find better programming languages that let the programmers develop correct code faster. The programming languages used today, typically C and/or Assemblers, are just too error-prone. The Java technology has therefore gained a lot of interest from developers of embedded systems in the last few years. We propose an approach based on compiling Java into native machine code via C as an intermediate language. The C code generation process should also add close interaction with a fully pre-emptive incremental garbage collector and a small and efficient real time kernel. Tests performed on a small 8-bit microprocessor show that it is possible to use a modern object oriented language with automatic memory management, such as Java, and yet generate fully predictable code that can be run in very small devices with severe memory constraints.
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| 20. |
- Nilsson, Anders, et al.
(författare)
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Implementing Java Compilers Using ReRAGs
- 2004
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Ingår i: Nordic Journal of Computing. - 1236-6064. ; 11:3, s. 213-234
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Tidskriftsartikel (refereegranskat)abstract
- Rewritable Reference Attributed Grammars (ReRAGs) is a recently developed compiler-compiler technology based on object-orientation, aspect-orientation, reference attributed grammars, and conditional rewrites. In this paper we describe our experiences from using ReRAGs for implementing Java compilers. We illustrate how the usage of ReRAGs renders a rather compact, yet easy-to-understand and modular compiler specification where code analysis, restructurings, and optimizations can be conveniently described as aspects performing computations and transformations on the abstract syntax tree. Currently, we have implemented two compilers: one that generates C code with real-time support, and one that generates Java bytecode. Both share the same front end.
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