Lab3 x86 source code

.text
.globl    _start

start = 0                       /* starting value for the loop index; note that this is a symbol (constant), not a variable */
max = 30                        /* loop exits when the index hits this
number (loop condition is i<max) */

_start:
    mov     $start,%r15         /* loop index */

loop:
    /* print the Loop message */
        movq    $loop_msg_len,%rdx                       /* message length */
        movq    $loop_msg,%rsi                       /* message location */
        movq    $1,%rdi                         /* file descriptor stdout */
        movq    $1,%rax                         /* syscall sys_write */
        syscall

    mov $num_msg_len, %r13
    mov %r15, %rax
    mov $0, %rdx
    div %r13

    /*Print the first digit */
        mov     $num_msg, %r14
        add     %rax, %r14
    mov $num_msg, %r13
    add %rdx, %r13

    cmp $0, %rax
    je skip

        movq    $1,%rdx                       /* message length */
    movq    %r14,%rsi                       /* message location */
        movq    $1,%rdi                         /* file descriptor stdout */
        movq    $1,%rax                         /* syscall sys_write */
        syscall
skip:
        /*Print the second digit */

        movq    $1,%rdx                       /* message length */
        movq    %r13,%rsi                       /* message location */
        movq    $1,%rdi                         /* file descriptor stdout */
        movq    $1,%rax                         /* syscall sys_write */
        syscall


    /* print the newline */
        movq    $nl_msg_len,%rdx                       /* message length */
        movq    $nl_msg,%rsi                       /* message location */
        movq    $1,%rdi                         /* file descriptor stdout */
        movq    $1,%rax                         /* syscall sys_write */
        syscall


    inc     %r15                /* increment index */
    cmp     $max,%r15           /* see if we're done */
    jne     loop                /* loop if we're not */

    mov     $0,%rdi             /* exit status */
    mov     $60,%rax            /* syscall sys_exit */
    syscall

.data

loop_msg:       .ascii  "Loop: "
loop_msg_len = . - loop_msg

num_msg:        .ascii "0123456789"
num_msg_len = . - num_msg

nl_msg:         .ascii "\n"
nl_msg_len = . - nl_msg