paizaでアセンブラ その５

概要

paizaでアセンブラ、やってみた。
gas調べたら、printf使えた。
fizzbuzzやってみた。

サンプルコード

import subprocess
import os

def gcc():
    c_file = 'fizzbuzz.s'
    test_c = """
.code64
.text
.global main

main:
    sub     $8, %rsp
    mov     $1, %r8
loop:
    mov     $0, %r10
    mov     $0, %rdx
    mov     %r8, %rax
    mov     $3, %rsi
    div     %esi
    cmp     $0, %rdx
    jne     skip1
    add     $1, %r10
skip1:
    mov     $0, %rdx
    mov     %r8, %rax
    mov     $5, %rsi
    div     %esi
    cmp     $0, %rdx
    jne     skip2
    add     $2, %r10
skip2:
    cmp     $0, %r10
    je      printNum
    cmp     $2, %r10
    jb      printFizz
    je      printBuzz
    ja      printFizzBuzz
printNum:
    lea     num(%rip), %rdi
    jmp     loope
printFizz:
    lea     fizz(%rip), %rdi
    jmp     loope
printBuzz:
    lea     buzz(%rip), %rdi
    jmp     loope
printFizzBuzz:
    lea     fizzbuzz(%rip), %rdi
loope:
    mov     $1, %rax
    mov     %r8, %rsi
    push    %r8
    push    %r10
    call    printf
    pop     %r10
    pop     %r8
    add     $1, %r8
    cmp     $101, %r8
    jne     loop
    add     $8, %rsp
    ret
.data
num:
    .asciz "%i "
fizz:
    .asciz "Fizz "
buzz:
    .asciz "Buzz "
fizzbuzz:
    .asciz "FizzBuzz "  
"""
    with open(c_file, 'w') as f:
        f.write(test_c)
    os.system("gcc -no-pie %s" % c_file)
    result = subprocess.Popen('./a.out', stdout = subprocess.PIPE).communicate()[0]
    for i, v in enumerate(result[ : -1].split('\n')):
        print v

if __name__ == '__main__':
  gcc()

成果物

以上。