[mattst88]

I suspect that the overwhelming majority of cases that warrant inline assembly would not benefit if it was instead a function call out to something you've linked in. That is, most inline assembly is a small snippet of optimized code that necessarily exists in the function you're optimizing.

[steveklabnik]

Yeah, as always, when we're considering stabilizing or removing something, we talk to who is using the feature and in what way, and these kinds of issues surface.

[pjmlp]

That is why naked and inline exist for.

[daeken]

Inline from C libraries won't -- as far as I'm aware -- inline into a Rust function. Inline is a compile-time hint, not a link-time behavior. In theory this could be changed in LLVM, but it seems really unlikely to me. The function exposed from C (with the inline asm) can be naked, though, assuming you are hygienic.

[pjmlp]

Yeah, but that is a consequence of not having a Rust aware linker and relying on one that basically uses C semantics.

Languages that use their own linkers tend to have better opportunities for code optimization during linking.