Bob Plantz <plantz@xxxxxxxx> writes: > I'm not aware of any 32-bit instructions that behave differently in > 64-bit mode. Except, of course, instructions that manipulate the stack > (push, pop, call, ret, etc.) do so in 32-bit or 64-bit increments, > respectively. This is the machine code 0x55 is pushl %ebp in 32-bit mode > and it is pushq %rbp in 64-bit mode. > > Do you have other examples? There are several 32-bit instructions which are invalid in 64-bit mode, such as aad, aas, etc. Ian
