> Do they just target the lowest common denominator of operations? Or do they somehow adapt to the operations supported by the user's CPU? Mostly the former, s

> Do they just target the lowest common denominator of operations? Or do they somehow adapt to the operations supported by the user's CPU? Mostly the former, some specialized software does the latter. The lowest common denominator is called the baseline, and it differs over time and between distributions. Debian for example still supports x86-64-v1 (the original 64-bit extension to x86), but RHEL 10 will require x86-64-v3, which includes SSE4 and AVX2 support.