Does Rust provide architecture-specific intrinsics like C/C++ toolchains usually do? That's a popular way to do SIMD.
[0] https://godbolt.org/z/85nx44zcE
edited: I tested gcc/clang and they just straight up fail to compile without -msse3. The generated code without optimizations is also pretty bonkers!
I guess the compiler itself might not know how those calls get resolved but the linker or cargo or some other mechanism might decide to include a library that provides stubs.
Why would anyone ever want that behavior? nop stubs could conceivably be used in some compiler isolated (no-execution) testing scenario but I'd expect it to be opt-in.