Problem Convert C If to Assembly Code Convert the following

Problem: Convert C (If) to Assembly Code.

Convert the following If Statement in C, to Assembly Language. Use: Subtract/Carrier-flag test and comparisons instructions. Comment each line of Assembly Code, for better understanding. unsigned char i, j; if (j >= 0 times 25) {j = j - i;}

Solution

Answer:

Assembly Language Code :

.zero 1
main:
push rbp
mov rbp, rsp
movzx eax, BYTE PTR [rbp-1]
cmp eax, 36
jle .L2
movzx eax, BYTE PTR [rbp-2]
sub BYTE PTR [rbp-1], al
.L2:
mov eax, 0
pop rbp
ret
__static_initialization_and_destruction_0(int, int):
push rbp
mov rbp, rsp
sub rsp, 16
mov DWORD PTR [rbp-4], edi
mov DWORD PTR [rbp-8], esi
cmp DWORD PTR [rbp-4], 1
jne .L6
cmp DWORD PTR [rbp-8], 65535
jne .L6
mov edi, OFFSET FLAT:std::__ioinit
call std::ios_base::Init::Init()
mov edx, OFFSET FLAT:__dso_handle
mov esi, OFFSET FLAT:std::__ioinit
mov edi, OFFSET FLAT:std::ios_base::Init::~Init()
call __cxa_atexit
.L6:
nop
leave
ret
push rbp
mov rbp, rsp
mov esi, 65535
mov edi, 1
call __static_initialization_and_destruction_0(int, int)
pop rbp
ret