It's even less likely than that: you'd have to be using x87/MMX and AVX-512 in the same part of the code. Essentially using the most obsolete and least obsolete

It's even less likely than that: you'd have to be using x87/MMX and AVX-512 in the same part of the code. Essentially using the most obsolete and least obsolete part of the ISA at the same time. Now that seems pretty unlikely.