/* @(#)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.
 * ====================================================
 */

#include <math.h>
#include <float.h>

#include "math_private.h"

float
nexttowardf(float x, long double y)
{
        int32_t hx,ix,iy;
        u_int32_t hy,ly,esy;

        GET_FLOAT_WORD(hx,x);
        GET_LDOUBLE_WORDS(esy,hy,ly,y);
        ix = hx&0x7fffffff;             /* |x| */
        iy = esy&0x7fff;                /* |y| */

        if((ix>0x7f800000) ||                   /* x is nan */
           (iy>=0x7fff&&((hy|ly)!=0)))          /* y is nan */
           return x+y;
        if((long double) x==y) return y;        /* x=y, return y */
        if(ix==0) {                             /* x == 0 */
            volatile float u;
            SET_FLOAT_WORD(x,((esy&0x8000)<<16)|1);/* return +-minsub*/
            u = x;
            u = u * u;                          /* raise underflow flag */
            return x;
        }
        if(hx>=0) {                             /* x > 0 */
            if(esy>=0x8000||((ix>>23)&0xff)>iy-0x3f80
               || (((ix>>23)&0xff)==iy-0x3f80
                   && ((ix&0x7fffff)<<8)>(hy&0x7fffffff))) {/* x > y, x -= ulp */
                hx -= 1;
            } else {                            /* x < y, x += ulp */
                hx += 1;
            }
        } else {                                /* x < 0 */
            if(esy<0x8000||((ix>>23)&0xff)>iy-0x3f80
               || (((ix>>23)&0xff)==iy-0x3f80
                   && ((ix&0x7fffff)<<8)>(hy&0x7fffffff))) {/* x < y, x -= ulp */
                hx -= 1;
            } else {                            /* x > y, x += ulp */
                hx += 1;
            }
        }
        hy = hx&0x7f800000;
        if(hy>=0x7f800000) {
          x = x+x;      /* overflow  */
          return x;
        }
        if(hy<0x00800000) {
            volatile float u = x*x;             /* underflow */
        }
        SET_FLOAT_WORD(x,hx);
        return x;
}