/* @(#)s_nextafter.c 5.1 93/09/24 */
/*
 * ====================================================
 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
 *
 * Developed at SunPro, a Sun Microsystems, Inc. business.
 * Permission to use, copy, modify, and distribute this
 * software is freely granted, provided that this notice
 * is preserved.
 * ====================================================
 */

/* IEEE functions
 *	nextafterl(x,y)
 *	return the next machine floating-point number of x in the
 *	direction toward y.
 *   Special cases:
 */



long double
nextafterl(long double x, long double y)
{
	int64_t hx,hy,ix,iy;
	u_int64_t lx,ly;

	GET_LDOUBLE_WORDS64(hx,lx,x);
	GET_LDOUBLE_WORDS64(hy,ly,y);
	ix = hx&0x7fffffffffffffffLL;		/* |x| */
	iy = hy&0x7fffffffffffffffLL;		/* |y| */

	if(((ix>=0x7fff000000000000LL)&&((ix-0x7fff000000000000LL)|lx)!=0) ||   /* x is nan */
	   ((iy>=0x7fff000000000000LL)&&((iy-0x7fff000000000000LL)|ly)!=0))     /* y is nan */
	   return x+y;
	if(x==y) return y;		/* x=y, return y */
	if((ix|lx)==0) {			/* x == 0 */
	    SET_LDOUBLE_WORDS64(x,hy&0x8000000000000000ULL,1);/* return +-minsubnormal */
            force_eval_long_double(x*x);
            return x;
	}
	if(hx>=0) {			/* x > 0 */
	    if(hx>hy||((hx==hy)&&(lx>ly))) {	/* x > y, x -= ulp */
		if(lx==0) hx--;
		lx--;
	    } else {				/* x < y, x += ulp */
		lx++;
		if(lx==0) hx++;
	    }
	} else {				/* x < 0 */
	    if(hy>=0||hx>hy||((hx==hy)&&(lx>ly))){/* x < y, x -= ulp */
		if(lx==0) hx--;
		lx--;
	    } else {				/* x > y, x += ulp */
		lx++;
		if(lx==0) hx++;
	    }
	}
	ix = hx&0x7fff000000000000LL;
	if(ix==0x7fff000000000000LL)
            return __math_oflowl(hy<0);
	SET_LDOUBLE_WORDS64(x,hx,lx);
	if(ix==0)
            return __math_denorml(x);
	return x;
}

#ifdef _HAVE_ALIAS_ATTRIBUTE
__strong_reference(nextafterl, nexttowardl);
#else
long double
nexttowardl(long double x, long double y)
{
    return nextafterl(x, y);
}
#endif
