euler1.s

# https://projecteuler.net/problem=1
# sum the nautural numbers below 10 that are multiples of 3 or 5

.section .text
.globl _start

_start:
  pushl $1 # counter
  pushl $0 # sum

loop_start:
  cmpl $10, 4(%esp)
  jge loop_end

  xorl %edx, %edx
  movl 4(%esp), %eax
  movl $3, %ebx
  idiv %ebx
  cmpl $0, %edx
  je add_number

  xorl %edx, %edx
  movl 4(%esp), %eax
  movl $5, %ebx
  idiv %ebx
  cmpl $0, %edx
  je add_number

  incl 4(%esp)
  jmp loop_start

add_number:
  movl 4(%esp), %eax
  addl %eax, (%esp)
  incl 4(%esp)
  jmp loop_start

loop_end:
  movl (%esp), %ebx
  movl $1, %eax
  int $0x80