Is there a better way to test the contribution of aliasing optimizations? Obviously the compiler could be patched, but that sort of invalidates the test because you'd have to assume I didn't screw up patching it somehow.
What I'm specifically interested in is how much more or less of a difference the class of optimizations makes on different calibers of hardware.
Well, the issue is that "aliasing optimizations" means different things in different languages, because what you can and cannot do is semantically different. The argument against strict aliasing in C is that you give up a lot and don't get much, but that doesn't apply to Rust, which has a different model and uses these optimizations much more.
For Rust, you'd have to patch the compiler, as they don't generally provide options to tweak this sort of thing. For both rust and C this should be pretty easy to patch, as you'd just disable the production of the noalias attribute when going to LLVM; gcc instead of clang may be harder, I don't know how things work over there.
