/* s_nextafterl.c -- long double version of s_nextafter.c.

 * Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz.

 */

/*

 * ====================================================

 * 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.

 * ====================================================

 */

#if defined(LIBM_SCCS) && !defined(lint)

static char rcsid[] = "$NetBSD: $";

#endif

/* IEEE functions

 *	nextafterl(x,y)

 *	return the next machine floating-point number of x in the

 *	direction toward y.

 *   Special cases:

 */

#include <errno.h>

#include <math.h>

#include <math-barriers.h>

#include <math_private.h>

#include <libm-alias-ldouble.h>

_Float128 __nextafterl(_Float128 x, _Float128 y)

{

	int64_t hx,hy,ix,iy;

	uint64_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 */

	    _Float128 u;

	    SET_LDOUBLE_WORDS64(x,hy&0x8000000000000000ULL,1);/* return +-minsubnormal */

	    u = math_opt_barrier (x);

	    u = u * u;

	    math_force_eval (u);		/* raise underflow flag */

	    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++;

	    }

	}

	hy = hx&0x7fff000000000000LL;

	if(hy==0x7fff000000000000LL) {

	    _Float128 u = x + x;		/* overflow  */

	    math_force_eval (u);

	    __set_errno (ERANGE);

	}

	if(hy==0) {

	    _Float128 u = x*x;		/* underflow */

	    math_force_eval (u);		/* raise underflow flag */

	    __set_errno (ERANGE);

	}

	SET_LDOUBLE_WORDS64(x,hx,lx);

	return x;

}

libm_alias_ldouble (__nextafter, nextafter)

strong_alias (__nextafterl, __nexttowardl)

weak_alias (__nextafterl, nexttowardl)