Comment by bsder

The only thing I would point out is that "free" FXCH isn't free. It has quite a lot of baggage inside the microprocessor and was something that designers made a conscious decision to support (see Pentium vs. AMD K5).

There are good reasons why hardware supports registers instead of a stack. However, given where x86 was at the time, the hardware designers of the time took the penalties because the gains to the software folks justified it.

Those choices no longer hold.