In Section 3.4.2, the x86-64 popq instruction was described as copying the result from...

In Section 3.4.2, the x86-64 popq instruction was described as copying the result from the top of the stack to the destination register and then incrementing the stack pointer. So, if we had an instruction of the form popq REG, it would be equivalent to the code sequence:

A. In light of analysis done in Problem 4.8, does this code sequence correctly describe the behavior of the instruction popq %rsp? Explain.

B. How could you rewrite the code sequence so that it correctly describes both the cases where REG is %esp as well as any other register?

Ref prb:

The following assembly- code function lets determine the behaviour of the instruction popq%rsp for x86-64:

We find this function always returns Oxabcd. What does this imply about the behavior of popq%rsp? What other Y86-64 instruction would have the exact same behaviour?