Sounds like you're advocating a different compiler ("based on"). Why not contribute directly to LLVM or GCC? Are there optimizations they'd need to do that are

Sounds like you're advocating a different compiler ("based on"). Why not contribute directly to LLVM or GCC? Are there optimizations they'd need to do that are incompatible with the wider goals of the open source project? I'm assuming the projects would be happy to accept new optimizations.