Question

Write a sequence of assembly language instructions to subtract each entry of an array A of five two’s complement 16-bit binary integers from the corresponding entry of an array B of five two’s complement 16-bit binary integers and construct a third array C of two’s complement 16-bit binary integers. i.e. C[i] = A[i] - B[i].

Use the following data for the arrays A and B.

A: 10, -15, 20, 4, -5

B: 25, -5, -30, 6, 10

please answer in computer assembler not c++

Answer 1

sub():

        push    rbp

        mov     rbp, rsp

        mov     DWORD PTR [rbp-32], 1

        mov     DWORD PTR [rbp-28], 2

        mov     DWORD PTR [rbp-24], 3

        mov     DWORD PTR [rbp-20], 4

        mov     DWORD PTR [rbp-16], 5

        mov     DWORD PTR [rbp-12], 6

        mov     DWORD PTR [rbp-64], 9

        mov     DWORD PTR [rbp-60], 8

        mov     DWORD PTR [rbp-56], 7

        mov     DWORD PTR [rbp-52], 5

        mov     DWORD PTR [rbp-48], 8

        mov     DWORD PTR [rbp-44], 3

        mov     DWORD PTR [rbp-4], 0

.L5:

        cmp     DWORD PTR [rbp-4], 4

        jg      .L2

        mov     eax, DWORD PTR [rbp-4]

        cdqe

        mov     edx, DWORD PTR [rbp-32+rax*4]

        mov     eax, DWORD PTR [rbp-4]

        cdqe

        mov     eax, DWORD PTR [rbp-64+rax*4]

        cmp     edx, eax

        jl      .L3

        mov     eax, DWORD PTR [rbp-4]

        cdqe

        mov     edx, DWORD PTR [rbp-32+rax*4]

        mov     eax, DWORD PTR [rbp-4]

        cdqe

        mov     eax, DWORD PTR [rbp-64+rax*4]

        sub     edx, eax

        mov     eax, DWORD PTR [rbp-4]

        cdqe

        mov     DWORD PTR [rbp-96+rax*4], edx

        jmp     .L4

.L3:

        mov     eax, DWORD PTR [rbp-4]

        cdqe

        mov     edx, DWORD PTR [rbp-64+rax*4]

        mov     eax, DWORD PTR [rbp-4]

        cdqe

        mov     eax, DWORD PTR [rbp-32+rax*4]

        cmp     edx, eax

        jle     .L4

        mov     eax, DWORD PTR [rbp-4]

        cdqe

        mov     edx, DWORD PTR [rbp-64+rax*4]

        mov     eax, DWORD PTR [rbp-4]

        cdqe

        mov     eax, DWORD PTR [rbp-32+rax*4]

        sub     edx, eax

        mov     eax, DWORD PTR [rbp-4]

        cdqe

        mov     DWORD PTR [rbp-96+rax*4], edx

.L4:

        add     DWORD PTR [rbp-4], 1

        jmp     .L5

.L2:

        mov     eax, DWORD PTR [rbp-76]

        pop     rbp

        ret