The very simple answer is, if you use the -O3 flag, then the compiler already automatically will use SIMD when appropriate (try a simple loop. Make sure you’ve re-built the system image or made Julia from the source). As for adding threading, the answer looks like it will be some macro (and you know about this since you’ve commented in the issue):
But…
What I am trying to get across is that those things will actually be packages. There are already many discussions about how to move the linear algebra parts out to a package, and it looks like it will be done before 1.0 (it’s waiting on the implementation of a system for default packages). Even the basic math functions like sqrt: Julia currently uses a version of OpenLibm, but there are some very advanced experiments with Julia implementations like Libm.jl and Amal.jl for replacing all of this basic math with packages (some packages may be loaded by default, but they will still just be packages).
So what I am really trying to hammer home is that the idea that “no it’s not Julia if it’s a package, let’s only talk about ‘Julia’” as though there is some privileged Base Julia which rules above all others: that idea is very wrongheaded. I think it’s safe to say that very soon, all of what you think of as “basic math operations” will be “default packages”: just standard Julia packages which by default are loaded into the system image.
So yes, even your examples of what do not refer to packages, actually refer to what will be packages. That means I think it’s safe to say you cannot talk about Julia as though it’s isolated from its package ecosystem. I think at this point, the concept of Julia includes packages, as seen by how things which were considered essential enough to be in early Julia have now moved out into packages. In that sense, you can already do what you’re asking in Julia using ParallelAccelerator, and the equivalent to Python+Numba in Julia is actually Julia+ParallelAccelerator.
Yes, that question hijacks the thread and all responses after it should be a separate thread about the future of auto-optimizing (SIMD, multi-threading, etc.) Julia code. Auto-optimizing Julia code a la Numba is something related to “making Julia fast”, but in some sense that is more about making Julia match hardware, not the design of Julia itself and why it makes sense as a way to specify scientific programs.