Compilation of LLVM IR at 1000x faster that -O0

I wonder if this could be a good path for compiling Rust: https://llvm.org/devmtg/2023-05/slides/StudentTalks-May11/01-Florian-TemplatedBasedCodeGenerationApproach-for-MLIR.pdf (later work by the same author includes an MIT licensed compiler for C)