/* long	ConvDecimalToLong(x)
 *
 * ARGUMENT
 *	DEC	*x;
 *
 * DESCRIPTION
 *	Converts a DEC to a long.
 *
 * SIDE	EFFECTS
 *	None.
 *
 * RETURNS
 *	The integer if the conversion is successful, and the error code
 * otherwise.
 *
 * POSSIBLE ERROR CODES
 *
 *	GM_NULLPOINTER
 *	GM_CNVRE
 *	GM_CNVRW
 *
 * AUTHOR
 *  Jared Levy	Feb. 9,	1987
 *   Copyright (C) 1987-1990 Greenleaf Software	Inc.  All rights reserved.
 *
 * MODIFICATIONS
 *
 */

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

long	ConvDecimalToLong(x)
DEC	*x;
{
	DEC	temp;
	DEC	*pt=&temp, dn, *n=&dn;
	mbool	wfIsNeg;
	long	l;
	unsigned long maxpos=2147483647L;

	_MacStart(GM_DTOL);
	_MacInVar(x, 0L);

	_MacDCopy(n, x);

/*
 * The following two lines of code shouldn't be	separated.  I ran into
 * a problem with Zortech v2.06.  If the _ScaleDec80Bit	is called right
 * after executing _MacIsDecN, the 0 in	the parameter list sometimes
 * gets	changed	to a -1.  This is bad.	Expect Zortech to fix it someday,
 * but since I only had	to change the order of execution of these three
 * lines, no need to change.  Same problem is found in DTOL.C.
 */
	(void) _ScaleDec80Bit(pt, n, 0);  /* convert to	integer	format */
	wfIsNeg	= _MacIsDecN(n);

/* |x| < 2147483648 */
	if ((pt->ls.lsl[1] == 0) && !(pt->ls.lsl[0] & 0x80000000/*UL*/)
		&& (pt->dc.msd == 0)) {
			l = (long) (pt->ls.lsl[0]);
			if (CompareDecimal(n,pt)!=0)
				_MacErr(GM_CNVRW);
			if (wfIsNeg)
				{_MacRet(-l)}
			else
				_MacRet(l);
			}

/* check for -2147483648 AND  "logical"	_MacRet	to get by MSC bug*/
	if (wfIsNeg && (pt->ls.lsl[0] == 0x80000000L) &&
	    (pt->ls.lsl[1] == 0) && (pt->ls.lmsd == 0))	 {
			if (CompareDecimal(n,pt)!=0)
				_MacErr(GM_CNVRW);
			_MacRet((long) ~maxpos);
		}

/* overflow */
	_MacErr(GM_CNVRE);
	_MacRet(0L);
}