We present FunTAL, the first multi-language system to formalize safe interoperability between a high-level functional language and low-level assembly code while supporting compositional reasoning about the mix. A cent...
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ISBN:
(纸本)9781450349888
We present FunTAL, the first multi-language system to formalize safe interoperability between a high-level functional language and low-level assembly code while supporting compositional reasoning about the mix. A central challenge in developing such a multi-language is bridging the gap between assembly, which is staged into jumps to continuations, and high-level code, where subterms return a result. We present a compositional stack-based typed assembly language that supports components, comprised of one or more basic blocks, that may be embedded in high-level contexts. We also present a logical relation for FunTAL that supports reasoning about equivalence of high-level components and their assembly replacements, mixed-language programs with callbacks between languages, and assembly components comprised of different numbers of basic blocks.
We present ***, a synchronous reactive language that adds synchronous concurrency and preemption to JavaScript. Inspired from Esterel, *** simplifies the programming of non-trivial temporal behaviors as found in compl...
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ISBN:
(纸本)9781450376136
We present ***, a synchronous reactive language that adds synchronous concurrency and preemption to JavaScript. Inspired from Esterel, *** simplifies the programming of non-trivial temporal behaviors as found in complex web interfaces or IoT controllers and the cooperation between synchronous and asynchronous activities. *** is compiled into plain sequential JavaScript and executes on unmodified runtime environments. We use three examples to present and discuss ***: a simple web login form to introduce the language and show how it differs from JavaScript, and two real life examples, a medical prescription pillbox and an interactive music system that show why concurrency and preemption help programming such temporal applications.
The Microsoft .NET Common language Runtime provides a shared type system, intermediate language and dynamic execution environment for the implementation and inter-operation of multiple source languages. In this paper ...
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ISBN:
(纸本)9781581134148
The Microsoft .NET Common language Runtime provides a shared type system, intermediate language and dynamic execution environment for the implementation and inter-operation of multiple source languages. In this paper we extend it with direct support for parametric polymorphism (also known as generics), describing the design through examples written in an extended version of the C# programminglanguage, and explaining aspects of implementation by reference to a prototype extension to the runtime. Our design is very expressive, supporting parameterized types, polymorphic static, instance and virtual methods, "F-bounded" type parameters, instantiation at pointer and value types, polymorphic recursion, and exact run-time types. The implementation takes advantage of the dynamic nature of the runtime, performing justin-time type specialization, representation-based code sharing and novel techniques for efficient creation and use of Nn-time types. Early performance results are encouraging and suggest that programmers will not need to pay an overhead for using generics, achieving performance almost matching hand-specialized code.
We present a new technique for removing unnecessary synchronization operations from statically compiled Java programs. Our approach improves upon current efforts based on escape analysis, as it can eliminate synchroni...
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ISBN:
(纸本)9781581131994
We present a new technique for removing unnecessary synchronization operations from statically compiled Java programs. Our approach improves upon current efforts based on escape analysis, as it can eliminate synchronization opt rations even on objects that escape their allocating threads. It makes use of a compact, equivalence-class-based representation that eliminates the need for fixed point operations during the analysis. We describe and evaluate the performance of an implementation in the Marmot native Java compiler. For the benchmark programs examined, the optimization removes 100% of the dynamic synchronization operations in single-threaded programs, and 0-99% in multi-threaded programs, at a low cost in additional compilation time and code growth.
Efficient communication and synchronization is crucial for fine-grained parallelism. Libraries providing such features, while indispensable, are difficult to write, and often cannot be tailored or composed to meet the...
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ISBN:
(纸本)9781450312059
Efficient communication and synchronization is crucial for fine-grained parallelism. Libraries providing such features, while indispensable, are difficult to write, and often cannot be tailored or composed to meet the needs of specific users. We introduce reagents, a set of combinators for concisely expressing concurrency algorithms. Reagents scale as well as their hand-coded counterparts, while providing the composability existing libraries lack.
Concepts are an essential language feature for generic programming in the large. Concepts allow for succinct expression of constraints on type parameters of generic algorithms, enable systematic organization of proble...
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Concepts are an essential language feature for generic programming in the large. Concepts allow for succinct expression of constraints on type parameters of generic algorithms, enable systematic organization of problem domain abstractions, and make generic algorithms easier to use. In this paper we present the design of a type system and semantics for concepts that is suitable for non-type-inferencing languages. Our design shares much in common with the type classes of Haskell, though our primary influence is from best practices in the C++ community, where concepts are used to document type requirements for templates in generic libraries. Concepts include a novel combination of associated types and same-type constraints that do not appear in type classes, but that are similar to nested types and type sharing in ML.
Type systems and syntactic sugar are both valuable to programmers, but sometimes at odds. While sugar is a valuable mechanism for implementing realistic languages, the expansion process obscures program source structu...
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ISBN:
(纸本)9781450356985
Type systems and syntactic sugar are both valuable to programmers, but sometimes at odds. While sugar is a valuable mechanism for implementing realistic languages, the expansion process obscures program source structure. As a result, type errors can reference terms the programmers did not write (and even constructs they do not know), baffling them. The language developer must also manually construct type rules for the sugars, to give a typed account of the surface language. We address these problems by presenting a process for automatically reconstructing type rules for the surface language using rules for the core. We have implemented this theory, and show several interesting case studies.
This paper describes an automated approach to hardware design space exploration, through a collaboration between parallelizing compiler technology and high-level synthesis tools. We present a compiler algorithm that a...
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This paper describes an automated approach to hardware design space exploration, through a collaboration between parallelizing compiler technology and high-level synthesis tools. We present a compiler algorithm that automatically explores the large design spaces resulting from the application of several program transformations commonly used in application-specific hardware designs. Our approach uses synthesis estimation techniques to quantitatively evaluate alternate designs for a loop nest computation. We have implemented this design space exploration algorithm in the context of a compilation and synthesis system called DE-FACTO, and present results of this implementation on five multimedia kernels. Our algorithm derives an implementation that closely matches the performance of the fastest design in the design space, and among implementations with comparable performance, selects the smallest design. We search on average only 0.3% of the design space. This technology thus significantly raises the level of abstraction for hardware design and explores a design space much larger than is feasible for a human designer.
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