I think there's an inherent conflation among people on ARM compatible versus ARM binaries that run on other arm platforms. This isn't the case with x86 today either, so it's weird when people say "oh look extensions mean it won't be ARM compatible". The core ISA is the same, which means the large majority of code will be portable, and people will have to go out of their way to use non portable instructions and intrinsics.
Being an undocumented extension doesn't matter. Compilers already handle per platform extensions on x86.
Being undocumented is better because it means people won't be targeting it in as high numbers, and therefore won't be making non portable code.
Being an undocumented extension doesn't matter. Compilers already handle per platform extensions on x86.
Being undocumented is better because it means people won't be targeting it in as high numbers, and therefore won't be making non portable code.