All of the memory-source instructions in Agner's guide don't really have a meaningful latency. In particular, the input and output domains are different. In th

All of the memory-source instructions in Agner's guide don't really have a meaningful latency. In particular, the input and output domains are different. In the case of pop, the input is memory and the output is a register, so you can't really measure the latency of pop in isolation: you need to chain it together with at least one other instruction whose inputs and outputs are in the opposite domain (eg push, or mov [memory], reg). Agner says himself that he "arbitrarily" divides the latency between load and store type instructions in these cases which gives the mostly meaningless value of 2 for load-type instructions.