Code transformation and instruction set extension

The demand for flexible embedded solutions and short time-to-market has led to the development of extensible processors that allow for customization through user-defined instruction set extensions (ISEs). These are usually identified from plain C sources. In this article, we propose a combined exploration of code transformations and ISE identification. The resulting performance of such a combination has been measured on two benchmark suites. Our results demonstrate that combined code transformations and ISEs can yield average performance improvements of 49%. This outperforms ISEs when applied in isolation, and in extreme cases yields a speed-up of 2.85.