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/* @(#)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:
*/
#include <math.h>
#include "math_private.h"
long double
nextafterl(long double x, long double y)
{
int32_t hx,hy,ix,iy;
u_int32_t lx,ly;
int32_t esx,esy;
GET_LDOUBLE_WORDS(esx,hx,lx,x);
GET_LDOUBLE_WORDS(esy,hy,ly,y);
ix = esx&0x7fff; /* |x| */
iy = esy&0x7fff; /* |y| */
if (((ix==0x7fff)&&(((hx&0x7fffffff)|lx)!=0)) || /* x is nan */
((iy==0x7fff)&&(((hy&0x7fffffff)|ly)!=0))) /* y is nan */
return x+y;
if(x==y) return y; /* x=y, return y */
if((ix|hx|lx)==0) { /* x == 0 */
volatile long double u;
SET_LDOUBLE_WORDS(x,esy&0x8000,0,1);/* return +-minsubnormal */
u = x;
u = u * u; /* raise underflow flag */
return x;
}
if(esx>=0) { /* x > 0 */
if(esx>esy||((esx==esy) && (hx>hy||((hx==hy)&&(lx>ly))))) {
/* x > y, x -= ulp */
if(lx==0) {
if ((hx&0x7fffffff)==0) esx -= 1;
hx = (hx - 1) | (hx & 0x80000000);
}
lx -= 1;
} else { /* x < y, x += ulp */
lx += 1;
if(lx==0) {
hx = (hx + 1) | (hx & 0x80000000);
if ((hx&0x7fffffff)==0) esx += 1;
}
}
} else { /* x < 0 */
if(esy>=0||(esx>esy||((esx==esy)&&(hx>hy||((hx==hy)&&(lx>ly)))))){
/* x < y, x -= ulp */
if(lx==0) {
if ((hx&0x7fffffff)==0) esx -= 1;
hx = (hx - 1) | (hx & 0x80000000);
}
lx -= 1;
} else { /* x > y, x += ulp */
lx += 1;
if(lx==0) {
hx = (hx + 1) | (hx & 0x80000000);
if ((hx&0x7fffffff)==0) esx += 1;
}
}
}
esy = esx&0x7fff;
if(esy==0x7fff) return x+x; /* overflow */
if(esy==0) {
volatile long double u = x*x; /* underflow */
if(u==x) {
SET_LDOUBLE_WORDS(x,esx,hx,lx);
return x;
}
}
SET_LDOUBLE_WORDS(x,esx,hx,lx);
return x;
}
DEF_STD(nextafterl);
MAKE_UNUSED_CLONE(nexttowardl, nextafterl);
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