Question

If we consider two registers ax and bx, how do we swap their contents in Intel IA-32 just by using push and pop? I’m not allowed to use xchg.

This is not question for a homework, I’m revising for an exam.

Answer 1

You can either push once and use a mov instruction, or push twice. First one goes like:

push ax
mov ax, bx
pop bx

If you want to push twice, it is (as answered by others):

push ax
push bx
pop ax
pop bx