Question

Convert this C++ program exactly as you see it into x86 assembly language:

// Use the Irvine library for the print function

#include <iostream>

// The string that needs to be printed

char word[] = "Golf\0";

// Pointer to a specific character in the string

char * character = word;

//NOTE: This main() function is not portable outside of Visual Studio

void main()

{

// Set up a LOOP - See the while loop's conditional expression below

int ecx = 4;

do

{

// Print the character

// In x86 assembly language you must use the following two lines of code:

// mov al, WHATEVER_CHARACTER_YOU_WANT_TO_PRINT

// call WriteChar

std::cout << *character;

// Increment the pointer

++character;

} while (--ecx != 0);

// In x86 assembly language you must use the following line of code:

// call CrLf

std::cout << std::endl;

// In x86 assembly language you must use the following line of code:

// call WaitMsg system("PAUSE");

}

Answer 1

word:

.string "Golf"

.string ""

character:

.quad word

main:

push rbp

mov rbp, rsp

sub rsp, 16

mov DWORD PTR[rbp-4], 4

.L3:

mov rax, QWORD PTR character[rip]

movzx eax, BYTE PTR [rax]

movsx eax, al

mov esi, eax

mov edi, OFFSET FLAT:_ZSt4cout

call std::basic_ostream<char, std::char_traits<char> >& std::operator<< <std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&, char)

mov rax, QWORD PTR character[rip]

add rax, 1

mov QWORD PTR character[rip], rax

sub DWORD PTR [rbp-4], 1

cmp DWORD PTR [rbp-4], 0

setne al

test al, al

je .L2

jmp .L3

.L2:

mov esi, OFFSET FLAT:_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_TO_ES6_

mov edi, OFFSET FLAT:_ZSt4cout

call std::basic_ostream<char, std::char_traits<char> >::operator<< (std::basic_ostream<char, std::char_traits<char> >& (*)(std::basic_ostream<char, std::char_traits<char> >&))

mov eax, 0

leave

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 .L7

cmp   DWORD PTR [rbp-8], 65535

jne .L7

mov edi, OFFSET FLAT:_ZStL8__ioinit

call std::ios_base::Init::Init() [complete object constructor]

mov edx, OFFSET FLAT:__dso_handle

mov esi, OFFSET FLAT:_ZStL8__ioinit

mov edi, OFFSET FLAT:_ZNSt8ios_base4InitD1Ev

call __cxa_atexit

.L7:

nop

leave

ret

_GLOBAL__sub_I_word:

push rbp

mov rbp, rsp

mov esi, 65535

mov edi, 1

call   __static_initialization_and_destruction_0(int, int)

pop rbp

ret