I'm pretty sure some of the AVX and SSE instructions are patented still, and those are accessible in user-mode and supported by Rosetta 2. Apple almost certain

I'm pretty sure some of the AVX and SSE instructions are patented still, and those are accessible in user-mode and supported by Rosetta 2. Apple almost certainly was able to either brow-beat Intel into a license, or design around the claims of said patents[0]. FWIW Apple has UI strings for when Rosetta 2 is disabled, so they might have had to consider cases where their license expires or something. [0] Notably I have no idea if patent claims on a hardware instruction & it's associated implementation would automatically prohibit emulation of that instruction, or if emulation would be a separate patentable.