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	▲	AlotOfReading 5 days ago
		`FilPizlonator drops flags in LLVM IR that would have permitted downstream passes to perform UB driven optimizations.` Does this work reliably or did your patches have to fix bugs here? There are LLVM bugs with floating point where backend doesn't properly respect passed attributes during codegen, which violate the behaviors of user level flags. I imagine the same thing exists for UB.
	▲	pizlonator 5 days ago \| parent [-]
		It works reliably. LLVM is engineered to be usable as a backend for type-safe/memory-safe languages. And those flags are engineered to work right for implementing the semantics of those languages, provided that you also do the work to avoid other LLVM pitfalls (and FilPizlonator does that work by inserting aggressive checks). Of course there could be a bug though. I just haven't encountered this particular kind of bug, and I've tested a lot of software (see https://fil-c.org/programs_that_work)