what is the addressing mode of dec with memory? (assembly x86)

Question

What is the addressing mode for the operations:

dec Z-2

mov bx, offset Z+3

? I could find most of the scenarios except this ones :/

thanks allot!

Answer 1

The first instruction dec Z-2 most probably uses a memory operand. I think however many assemblers would prefer something like dec word [Z-2] . Written this way the instruction decrements the word before label/variable Z.

The second instruction mov bx,offset Z+3 uses an immediate operand whose value is 3 more than the address of the label/variable Z. It doesn't approach the memory whose address was calculated.