/* DEC	*ArcTangentDecimal(pDst,pSrc)
 *
 * ARGUMENT
 *	DEC	*pDst;
 *	DEC	*pSrc;
 *
 * DESCRIPTION
 *	Sets pDst = the	arctangent (in radians)	of pSrc,
 *  which always lies between -pi/2 and	pi/2.
 *
 * RETURNS
 *	Returns	pointer	to pDst	if successful, otherwise a GM_NULL.
 *
 * POSSIBLE ERROR CODES
 *
 *	GM_NULLPOINTER
 *	GM_NOMEMORY
 *
 * AUTHOR
 *  Jared Levy		Aug 7, 1987
 *   Copyright (C) 1987-1990 Greenleaf Software	Inc.  All rights reserved.
 *
 * MODIFICATIONS
 *
 */

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

DEC	*ArcTangentDecimal(pDst,pSrc)
DEC	*pDst;
DEC	*pSrc;
{

	_MacStart(GM_DATAN);

	_MacInVar(pSrc,GM_NULL);
	_MacOutVar(pDst,GM_NULL);

	_ATanDec80Bit(pDst, pSrc);

	/* reduce from 80-bit back to 64-bit */
	(void) _Sq5UnsTo4Uns(pDst);

	_MacRet(pDst);
}