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However, I do see a potential issue with the compiler assuming that code after the final asm() block is reachable, and calling unreachable() is not permitted [by Clang] due to the __naked attribute. > As far as the compiler is concerned, there is "nothing" after the last > asm() block. It can be marked with noreturn attribute, but I don't > know how it interacts with the naked attribute. You can't use __builtin_unreachable() in a naked function.  I was going to suggest it against v1, but alas. ~Andrew