I believe the intention here is to use the super-optimiser to derive specific generally-applicable optimisations that can be contributed back to LLVM as peephol

I believe the intention here is to use the super-optimiser to derive specific generally-applicable optimisations that can be contributed back to LLVM as peephole optimisations, rather than running the super-optimiser as part of the usual compilation process. That being the case, it seems like it would be advantageous to create optimisations that work at both stages of compilation - not least because the IR-level ones will be more widely applicable.