An Experiment Combining Specialization with Abstract Interpretation

It was previously shown that control-flow refinement can be achieved by a program specializer incorporating property-based abstraction, to improve termination and complexity analysis tools. We now show that this purpose-built specializer can be reconstructed in a more modular way, and that the previous results can be achieved using an off-the-shelf partial evaluation tool, applied to an abstract interpreter. The key feature of the abstract interpreter is the abstract domain, which is the product of the property-based abstract domain with the concrete domain. This language-independent framework provides a practical approach to implementing a variety of powerful specializers, and contributes to a stream of research on using interpreters and specialization to achieve program transformations.Comment: In Proceedings VPT/HCVS 2020, arXiv:2008.0248

The next 700 program transformers

In this paper, we describe a hierarchy of program transformers, capable of performing fusion to eliminate intermediate data structures, in which the transformer at each level of the hierarchy builds on top of those at lower levels. The program transformer at level 1 of the hierarchy corresponds to positive supercompilation, and that at level 2 corresponds to distillation. We give a number of examples of the application of our transformers at different levels in the hierarchy and look at the speedups that are obtained. We determine the maximum speedups that can be obtained at each level, and prove that the transformers at each level terminate

Program Transformation with Metasystem Transitions: Experiments with a Supercompiler

Turchin's supercompilation is a program transformation technique for functional languages. A supercompiler is a program which can perform a deep transformation of programs using a principle which is similar to partial evaluation. In the present paper we use a supercompiler, which V.F. Turchin and we have described in [22], [23]. The aim of our investigation has been to show, what deep changes ( w.r.t. run time ) in the programs can be achieved by supercompilation. In [21] V.F. Turchin presented a method to improve the transformational power of supercompilation without modifying the transformation system. We use this idea to show both the power of the method and abilities of our supercompiler. Our examples include a generation of both one-step unfolding and instantiations, lazy evaluation, inverse evaluation. Keywords: program transformation, optimization, recursion, supercompilation, metacomputation, metasystem transition, Refal. 1 Introduction Turchin's supercompilation is a progr..