; intfunc.asm  call integer function  int sum(int x, int y)
; 
; compile:	nasm -f elf intfunc.asm 
; link:		gcc -o intfunc.o
; run:		intfunc
; result:	5 = sum(2,3)

	extern	printf
	section .data
x:	dd	2
y:	dd	3
z:	dd	1
fmt:	db	"%d = sum(%d,%d)",10,0
	global	main
main:	push	ebp
	mov	ebp,esp
	push	ebx

	push	dword [y]	; push arguments for sum
	push	dword [x]
	call	sum		; coded below
	add	esp,8
	mov	[z],eax		; save result from sum

	push	dword [y]	; print
	push	dword [x]
	push	dword [z]
	push	dword fmt
	call	printf
	add	esp,16

	pop	ebx
	mov	esp,ebp
	pop	ebp
	mov	eax,0
	ret
; end main

sum:	push	ebp		; function int sum(int x, int y)
	mov	ebp,esp
	push	ebx

	mov	eax,[ebp+8]	; get argument x
	mov	ebx,[ebp+12]	; get argument y
	add	eax,ebx		; x+y with result in eax

	pop	ebx
	mov	esp,ebp
	pop	ebp
	ret			; return value in eax
; end of function  int sum(int x, int y)