abstract = "Genetic improvement uses automated search to find
improved versions of existing software. Genetic
improvement has previously been concerned with
improving a system with respect to all possible usage
scenarios. In this paper, we show how genetic
improvement can also be used to achieve specialisation
to a specific set of usage scenarios. We use genetic
improvement to evolve faster versions of a C++ program,
a Boolean satisfiability solver called MiniSAT,
specialising it for three applications. Our specialised
solvers achieve between 4percent and 36percent
execution time improvement, which is commensurate with
efficiency gains achievable using human expert
optimisation for the general solver. We also use
genetic improvement to evolve faster versions of an
image processing tool called ImageMagick, using code
from GraphicsMagick, another image processing tool
which was forked from it. We specialise the format
conversion functionality to black and white images and
colour images only. Our specialised versions achieve up
to 3percent execution time improvement.",