ZMM registers are separate from the 8 FPU registers. That's because the ZMM set is separate from MM registers. So there's 8 more. In hardware, however, renamin

ZMM registers are separate from the 8 FPU registers. That's because the ZMM set is separate from MM registers. So there's 8 more. In hardware, however, renaming resources are shared between ST/MM registers and the eight Kn mask registers.