zombie-lib/atoi_legacy.asm

88 lines
817 B
NASM

extern libz_strlen
global libz_atoi
section .text
libz_atoi:
mov r8, rdi
xor r9, r9
_loopasd23:
mov r9b, [r8]
cmp r9, 0 ;check and see if we have reached the end of the string
jz _exitloopasd12
sub r9, 48
mov [r8], r9b
inc r8
jmp _loopasd23
_exitloopasd12:
call libz_strlen
mov r8, rax
mov r11, rax
add r8, rdi
dec r8
push r8
inc r8
mov rcx, 1
_loop2asd12:
dec r8
mov al, [r8]
mul rcx
mov [r8], al
mov rax, rcx
mov r10, 10
mul r10
mov rcx, rax
cmp r8, rdi
je _exitloop2asd12
jmp _loop2asd12
_exitloop2asd12:
mov r8, rdi
mov r9, rdi
inc r9
_loop3asd12:
mov r11b, [r9]
mov r10b, [r8]
cmp r11, 0
jz _endasdasd23123
add r11, r10
mov [r9], r11b
mov [r8], r10b
inc r8
inc r9
jmp _loop3asd12
_endasdasd23123:
pop r8
mov rax, [r8]
ret