%define x1	qword  [EBP + 8]
%define x2	qword  [EBP + 16]
%define y1	qword  [EBP + 24]
%define y2	qword  [EBP + 32]
%define d	dword  [EBP + 40]

%include "asm_io.inc"

segment .text
	global	_distance
_distance:
	push		ebp
	mov		ebp, esp
	push		ebx

	fld		x1		; stack = x1

	fsub		x2		; stack = (x1-x2)
	fmul		st0		; stack = (x1-x2)2
	fld		y1		; stack = y1   (x1-x2)2
	fsub		y2		; stack = (y1-y2) (x1-x2)2
	fmul		st0		; stack = (y1-y2)2 (x1-x2)2
	fadd		st1		; stack = d2  (x1-x2)2
	fsqrt				; stack = d    (x1-x2)2

	mov		ebx, d
	fst		qword [ebx]	; write d to memory

	pop		ebx
	pop		ebp
	ret