Anything in regard to using less locals and more nesting, like previously:

a(b(c)) became int val = b(c) a(val)

even though val never was used anymore after this

Either way pretty cool!

Don't think that particular optimization was ever implemented. It looks straightforward, but one does have to be careful about re-ordering, so the legality check is slightly more complicated. We briefly considered writing a clang-based source-to-source transformation as a post processing pass to clean up, but it wasn't worth it for our use case.