Extending GCC with modular GIMPLE optimizations

We present a system of plug-ins for GCC that allows GCC to load GIMPLE transformations at run-time. This system reduces the support effort required for GCC by separating transformations from the core compiler. It also makes it possible for developers not connected with the GCC project to develop and distribute transformations independently. We demonstrate two plug-ins we have developed with this system, one of which reduces the effort required to develop transformations significantly by allowing visualization of the GCC controlflow graph and the GIMPLE tree structure. We enumerate portions of the compiler that could be extracted into plug-ins, and describe future applications of the plug-in system.