People should be aware though that without `-C target_feature=+<feature>` in your rustc flags the compiler may emit function calls to stubs for the intrinsic. So people should make sure they're passing the appropriate target features, especially when benchmarking.
> compiler may emit function calls to stubs for the intrinsic.
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.
[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!