@subtype if i recall the spec (and it has been a while) wasm really only defines kinda normal cpu logic, and then tries to store the control flow graph in a structured form (because they hate gotos, and don't want the wasm runtimes to have to recover the control flow graph when transpiling), and things like AVX instructions are exiled to being functions you import from the runtime (like it works for GCC intrinsics) and they turn it in to what it should be, if they can, on their end.