If the codebase is small, and the dependencies are minimal, you might look into trying to integrate your rcc in "bootstrapping" flows, which currently often rely on tcc as a stepping stone towards gcc. And perhaps even being able to skip gcc 4.7 in favor of your compiler, if it's capable of, say, compiling a modern gcc to work even suboptimally.

tcc is pretty good for this.

What I want to explore is cheap and fast optimizations, without SSA and data flow tracking. I have huge sources files compiled to 25MB .o files, which should need to be compiled in less than 5m. So far only tcc can do that. But I have now consteval and deadcode elimination for free. Which tcc cannot do.