Question

translate c++ to mips

bool
singleton(int value) {
//Check condition
if (value == 0)

//Return
return false;

//Declare and initialize
int compare = value-1;
bool isTrue = value & compare;

//Check condition
if (isTrue == 0)

//Return
return true;

//Otherwise
else

//Return
return false;
}

Answer 1

MIPS Code:

singleton(int):
push rbp
mov rbp, rsp
mov DWORD PTR [rbp-20], edi
cmp DWORD PTR [rbp-20], 0
jne .L2
mov eax, 0
jmp .L3
.L2:
mov eax, DWORD PTR [rbp-20]
sub eax, 1
mov DWORD PTR [rbp-4], eax
mov eax, DWORD PTR [rbp-20]
and eax, DWORD PTR [rbp-4]
test eax, eax
setne al
mov BYTE PTR [rbp-5], al
movzx eax, BYTE PTR [rbp-5]
test eax, eax
jne .L4
mov eax, 1
jmp .L3
.L4:
mov eax, 0
.L3:
pop rbp
ret

Code Screenshot:

Line-wise Explanation:

1) bool singleton(int value)

push rbp
mov rbp, rsp
mov DWORD PTR [rbp-20], edi

2) if (value == 0)
return false;

cmp DWORD PTR [rbp-20], 0
jne .L2

3) int compare = value-1;

mov eax, DWORD PTR [rbp-20]
sub eax, 1
mov DWORD PTR [rbp-4], eax

4) bool isTrue = value & compare;

mov eax, DWORD PTR [rbp-20]
and eax, DWORD PTR [rbp-4]
test eax, eax
setne al
mov BYTE PTR [rbp-5], al

5) if (isTrue == 0)
return true;

movzx eax, BYTE PTR [rbp-5]
test eax, eax
jne .L4
mov eax, 1
jmp .L3

6) else
return false;

.L4:
mov eax, 0

7) End of the program

.L3:
pop rbp
ret

Note: For any doubt please feel free to comment.