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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)
{
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 */
volatile long double u;
SET_LDOUBLE_WORDS64(x,hy&0x8000000000000000ULL,1);/* return +-minsubnormal */
u = x;
u = u * 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) return x+x;/* overflow */
if(hy==0) {
volatile long double u = x*x; /* underflow */
}
SET_LDOUBLE_WORDS64(x,hx,lx);
return x;
}
DEF_STD(nextafterl);
MAKE_UNUSED_CLONE(nexttowardl, nextafterl);
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