include mc.ash
.model small
;
;Support routines for PRINTF.C
;
;Tom Jennings
;22 Jan 92
;
.code
;/*
;	Internal routine used by "_spr" to perform ascii-
;	to-decimal conversion and update an associated pointer:
;*/
;
;int _gv2(sptr)
;char **sptr;
;{
;int n;
;	n = 0;
;	while (isdigit(**sptr)) n = 10 * n + *(*sptr)++ - '0';
;	return(n);
;}
func __gv2
	push	si
	mov	si,arg0		;SI= *sptr
	mov	bx,[si]		;BX= sptr
	mov	dx,0		;N= 0
	mov	ah,0

gv1:	mov	al,[bx]		;AL= *sptr
	sub	al,'0'		;
	jc	gvz		; < '0'
	cmp	al,10
	jnc	gvz		; > '9'

	add	dx,dx		; N *= 2
	mov	cx,dx		; (save that)
	add	dx,dx		; N *= 4
	add	dx,dx		; N *= 8
	add	dx,cx		; N *= 10
	add	dx,ax		; + digit
	inc	bx
	jmp	gv1

gvz:	mov	[si],bx
	pop	si
	mov	ax,dx
endf __gv2

	end