I think the Zen 2 reasons about the operations and operands and converts them into something like these micro-ops and then schedules them for a functional unit

I think the Zen 2 reasons about the operations and operands and converts them into something like these micro-ops and then schedules them for a functional unit and the renamer: functional unit renamer add tmp_reg, eax, 5 st [rsi], tmp_reg mov ebx, temp_reg Consequently, I don't think you can use the latency tables directly to get "2". I think Agner probably got those 15 and 2 aggregate numbers from measuring them directly rather than calculating them from the latency tables. BTW, I'm hand waving on the micro-ops and FUs. There's probably some address generation, ... going on that I'm leaving out. I don't even think the renamer requires a translated micro-op. You could replace tmp_reg with renamed(ebx). Now the downside. What happens at an exception? You have to back all of this optimization out.