Question

1. Construct an assembly language program fragment equivalent to the following C/C++ statement:

if (M <= N + 3 && (C == ‘N’ || C == ‘n’))

C = ‘0’;

else

C = ‘1’;

Assume that M and N are 32-bit signed integer variables, and C is an 8-bit ASCII character variable. All variables are stored in memory, and all general-purpose registers are available for use.

Answer 1

main:

        push    rbp

        mov     rbp, rsp

        mov     eax, DWORD PTR [rbp-4]

        add     eax, 3

        cmp     DWORD PTR [rbp-8], eax

        jg      .L2

        cmp     BYTE PTR [rbp-9], 78

        je      .L3

        cmp     BYTE PTR [rbp-9], 110

jne     .L2

.L3:

        mov     BYTE PTR [rbp-9], 48

        jmp     .L4

.L2:

        mov     BYTE PTR [rbp-9], 49

.L4:

        mov     eax, 0

        pop     rbp

        ret