/* DEC	*SumDecimalArrayPositive(pDst,pSrc,n)
 *
 * ARGUMENT
 *	DEC	*pDst;
 *	DEC	**pSrc;
 *	int n;
 *
 * DESCRIPTION
 *	Sets pDst to the sum of	the n DEC elements of the array	pSrc.
 *   If	n is 0,	0 is returned.	pDst is	unchanged if an	error occurs.
 *   Only the positive elements	are added.
 *
 * SIDE	EFFECTS
 *	None.
 *
 * RETURNS
 *	Returns	pointer	to the sum if successful, otherwise
 *   returns GM_NULL.
 *
 * POSSIBLE ERROR CODES
 *
 *	GM_NULLPOINTER
 *	GM_ARGVAL
 *
 * AUTHOR
 *	Jared Levy
 *   Copyright (C) 1987-1990 Greenleaf Software	Inc.  All rights reserved.
 *
 * MODIFICATIONS
 *
 */

#include <stdio.h>
#include "gm.h"
#include "gmsystem.h"

DEC	*SumDecimalArrayPositive(pDst,pSrc,n)
DEC	*pDst;
DEC	**pSrc;
int n;
{
	int i;
	DEC	*p, dsum, *sum=&dsum;

/*  source must	be supplied !! */
	_MacStart(GM_SUMARRP);

	if (!pSrc||!pDst) {
		_MacErr(GM_NULLPOINTER);
		_MacRet(GM_NULL);
	}

	if (n<0)  {
		_MacErr(GM_ARGVAL);
		_MacRet(GM_NULL);
	}

	for (i=0; i<n; i++)  {
		_MacInVar(pSrc[i],GM_NULL);
		}

	_MacDZero(sum);
	for (i=0;i<n;i++)  {
		p = pSrc[i];
		if (_MacIsDecP(p))
			(void) _AddDec80Bit(sum, sum, p);
		/* overflow impossible here since sum is 80 bits */
	}

/* sum must be 64 bits */
	if (_Sq5UnsTo4Uns(sum) != GM_SUCCESS)  {
		_MacErr(GM_OVERFLOW);
		_MacRet(GM_NULL);
	}

	_MacDCopy(pDst,sum);
	_MacRet(pDst);
}