Comment by m-hilgendorf

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.

[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!