alt Hacker Newsi am quietly waiting for the "bitter lesson" to hit compilers: a large language model that speaks in LLVM IR tokens that takes unoptimized IR from the frontend, and spits out an optimized version that works better than any "classical" compiler.
the only thing that might stand in the way is a dependence on reproducibility, but it seems like a weak argument: We already have a long history of people trying to push build reproducibility, and for better or worse they never got traction.
same story with LTO and PGO: I can't think of anyone other than browser and compiler people who are using either (and even they took a long time before they started using them). judged to be more effort than its worth i guess.
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Us video game folks are big fans of LTO, PGO, FDO, etc.
How's it going in the other direction - LLMs as disassemblers?
I tried it a year or so back and was sorta disappointed at the results beyond simple cases, but it feels like an area that could improve rapidly.
The major constraint is that the compiler needs to guarantee that transformations produce semantically identical results to the unoptimized code, with the exception of undefined behavior or specific opt-outs (eg. `-ffast-math` rules).
An ML model can fit into existing compiler pipelines anywhere that heuristics are used though, as an alternative to PGO.