[fredoralive]

I think they mean that using the raw instructions is unsupported and undocumented, officially you have to use the libraries as the interface to them.

[cyber_kinetist]

Though in reality nobody is stopping you from using those undocumented instructions. If Apple’s Accelerate framework can use it so do you. (Or is it against the EULA?…) There is a slim chance that the behavior of these instructions might change with a software (if Apple is doing any kind of microcode update), but I kinda doubt it.