Papers

Fixing Bugs in Your Sleep: How Genetic Improvement Became an Overnight Success
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Saemundur Oskar Haraldsson, John R. Woodward, Alexander E.I. Brownlee, and Kristin Siggeirsdottir

We present a bespoke live system in commercial use with self-improving capability. During daytime business hours it provides an overview and control for many specialists to simultaneously schedule and observe the rehabilitation process for multiple clients. However in the evening, after the last user logs out, it starts a self-analysis based on the day’s recorded interactions. It generates test data from the recorded interactions for Genetic Improvement to fix any recorded bugs that have raised exceptions. The system has already been under test for over 6 months and has in that time identified, located, and fixed 22 bugs. No other bugs have been identified by other methods during that time. It demonstrates the effectiveness of simple test data generation and the ability of GI for improving live code.

Embedding Genetic Improvement into Programming Languages
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Shin Yoo

We present a vision of genetic improvement firmly embedded in, and supported by, programming languages. Genetic improvement has already been envisioned as the next compiler, which would take human written programs as input and return versions optimised with respect to various objectives. As an intermediate stage, or perhaps to complement the fully automated vision, we imagine genetic improvement processes that are hinted at and directed by humans but understood and undertaken by programming languages and their runtimes, via interactions through the source code. We examine existing similar ideas and examine the benefits of embedding them within programming languages.

Learning from Super-Mutants
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Jason Landsborough, Stephen Harding and Sunny Fugate

In light of recent advances in genetic-algorithm-driven automated program modification, our team has been actively exploring the art, engineering, and discovery of novel semantics-preserving transforms. While modern compilers represent some of the best ideas we have for automated program modification, current approaches represent only a small subset of the types of transforms which can be achieved. In the wilderness of post-apocalyptic software ecosystems of genetically-modified and mutant programs, there exist a broad array of potentially useful software mutations, including semantics-preserving transforms that may play an important role in future software design, development, and most importantly, evolution.

Deep Parameter Optimisation on Android Smartphones for Energy Minimisation – A Tale of Woe and a Proof-of-Concept
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Mahmoud A. Bokhari, Bobby R. Bruce, Brad Alexander and Markus Wagner

With power demands of mobile devices rising, it is becoming increasingly important to make mobile software applications more energy efficient. Unfortunately, mobile platforms are diverse and very complex which makes energy behaviours difficult to model. is complexity presents challenges to the effectiveness of online optimisation of mobile applications. In this paper, we demonstrate that it is possible to automatically optimise an application for energy on a mobile device by evaluating energy consumption in-vivo. In contrast to previous work, we use only the device’s own internal meter. Our approach involves many technical challenges but represents a realistic path toward learning hardware specific energy models for program code features.

Evolving Software Building Blocks with FINCH
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Michael Orlov

This paper proposes to explore the following question: can software evolution systems like FINCH, that evolve linear representations originating from a higher-level structural language, take advantage of building blocks inherent to that original language?

GI in No Time
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David R. White

We describe a small, simple, and lightweight microframework for the Genetic Improvement of Java code. We call the framework “GI in no time”, or “Gin”. Gin is designed to be a straightforward, hackable, GI tool for Java. It currently lacks large features found in comparable program repair tools, but nonetheless it is capable of performing optimisation of a Java class via local search. We hope that providing this contribution will encourage researchers to collaborate on GI tool development, whilst lowering the barrier to entry for those interested in experimenting with GI. It is intended to serve both as a toolkit to be extended, and also an example of how GI can be implemented. We discuss some of the design principles behind Gin, and outline observations made during its development.

Gaining Insights into Traffic Data through Genetic Improvement
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Aniko Ekart, Alina Patell, Victoria Lush, and Elisabeth Ilie-Zudor

We argue that Genetic Improvement can be successfully used for enhancing road traffic data mining. Thiis would support the relevant decision makers with extending the existing network of devices that sense and control city traffic, with the end goal of improving vehicle flow and reducing the frequency of road accidents. Our position results from a set of preliminary observations emerging from the analysis of open access road traffic data collected in real time by the Birmingham City Council.

New Operators for Non-functional Genetic Improvement
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Justyna Petke

Genetic improvement uses automated search to find improved versions of existing software. Typically software is modified using either delete, copy or replace operations at the level of source code, its abstract syntax tree, binary or assembly representation. Impressive improvements have been achieved through this approach, yet research in the use of other search operators is largely unexplored. We propose several ways for devising new search operators for improvement of non-functional properties using a genetic improvement approach.

Modelling Genetic Improvement Landscapes with Local Optima Networks
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Nadarajen Veerapen, Fabio Daolio and Gabriela Ochoa

Local optima networks are a compact representation of the global structure of a search space. They can be used for analysis and visualisation. This paper provides one of the first analyses of program search spaces using local optima networks. These are generated by sampling the search space by recording the progress of an Iterated Local Search algorithm. Source code mutations in comparison and Boolean operators are considered. The search spaces of two small benchmark programs, the triangle and TCAS programs, are analysed and visualised. Results show a high level of neutrality, i.e. connected test-equivalent mutants. It is also generally relatively easy to find a path from a random mutant to a mutant that passes all test cases.

Genetic Improvement of Runtime in a Bioinformatics Application
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Saemundur Oskar Haraldsson, John R. Woodward, Alexander E.I. Brownlee, Albert V. Smith and Vilmundur Gudnason

We present a Genetic Improvement (GI) experiment on ProbAbel, a piece of bioinformatics software for Genome Wide Association (GWA) studies. The GI framework used here has previously been successfully used on Python programs and can, with minimal adaptation, be used on source code written in other languages. We achieve improvements in execution time without the loss of accuracy in output while also exploring the vast fitness landscape that the GI framework has to search. The runtime improvements achieved on smaller data set scale up for larger data sets. Our findings are that for ProbAbel, the GI’s execution time landscape is noisy but flat. We also confirm that human written code is robust with respect to small edits to the source code.

Improving SSE Parallel Code with Grow and Graft Genetic Programming
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W Langdon and R Lorenz

RNAfold predicts the secondary structure of RNA molecules from their base sequence. We apply a mixture of manual and automated genetic improvements to its C source. GI gives a 1.6% improvement to parallel SSE4.1 code. The automatic programming evolutionary system has access to Intel library code and previous revisions. On 4666 curated structures from RNA STRAND, GGGP gives a combined speed up of 31.9%, with no loss of accuracy (GI code run 1.4e11 times).

From Problem Landscapes to Language Landscapes: Questions in Genetic Improvement
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Brendan Cody-Kenny, Michael Fenton and Michael O’Neill

Managing and curating software is a time consuming process particularly as programming languages, libraries, and execution environments change. To support the engineering of software, we propose applying a GP-based continuous learning system to all “useful” software. We take the position that search-based itemization and analysis of all commonly used software is feasible, in large part, because the requirements that people place on software can be used to bound the search space to software which is of high practical use. By repeatedly reusing the information generated during the search process we hope to attain a higher-level, but also more rigorous, understanding of our engineering material – source code.