It's nothing new. Most of us might think one instruction will only do one thing but it's actully much more complicated than that. Instructions can actually be b

It's nothing new. Most of us might think one instruction will only do one thing but it's actully much more complicated than that. Instructions can actually be broken down to multiple steps and some of those are in common. And thus modern CPUs have a concept of μOp which refers to aforementioned step. What and especially how an instruction does things can be updated by uploading a new firmware to the CPU.