Linux-Shellcodes-x86/arithmetic.nasm at master · ojardila/Linux-Shellcodes-x86 · GitHub

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global _start
section .text

_start:

  ; Register ased addition
  mov eax, 0
  add al, 0x22
  add al, 0x11

  mov ax, 0x1122
  add ax, 0x3344

  mov eax, 0xffffffff
  add eax, 0x10

  mov eax, 0
  add byte [var1], 0x22
  add byte [var1], 0x11

  add word [var2], 0x1122
  add word [var2], 0x3344
  mov dword [var3], 0xffffffff
  add dword [var3], 0x10

  clc
  stc
  cmc

  ; add with carry
  mov eax, 0
  stc
  adc al, 0x22
  stc
  adc al, 0x11


  mov ax, 0x1122
  stc
  adc ax, 0x3344

  mov eax, 0xffffffff
  stc
  adc eax, 0x10

  ; substract

  mov eax, 10
  sub eax, 5
  stc
  sbb eax, 4
  ; increment and decrement

  inc eax
  dec eax

  ; exit program
  mov eax, 1
  mov ebx, 10
  int 0x80


section .data

  var1 db 0x00
  var2 dw 0x000
  var3 dd 0x00000000