mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-23 13:30:06 +00:00
125 lines
3.0 KiB
C
125 lines
3.0 KiB
C
/* s_nextafterl.c -- long double version of s_nextafter.c.
|
|
* Special version for i387.
|
|
* Conversion to long double by Ulrich Drepper,
|
|
* Cygnus Support, drepper@cygnus.com.
|
|
*/
|
|
|
|
/*
|
|
* ====================================================
|
|
* 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 "math.h"
|
|
#include "math_private.h"
|
|
|
|
#ifdef __STDC__
|
|
long double __nextafterl(long double x, long double y)
|
|
#else
|
|
long double __nextafterl(x,y)
|
|
long double x,y;
|
|
#endif
|
|
{
|
|
u_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| */
|
|
|
|
/* Intel's extended format has the normally implicit 1 explicit
|
|
present. Sigh! */
|
|
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 */
|
|
SET_LDOUBLE_WORDS(x,esy&0x8000,0,1);/* return +-minsubnormal */
|
|
y = x*x;
|
|
if(y==x) return y; else return x; /* raise underflow flag */
|
|
}
|
|
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 <= 0x80000000) {
|
|
if (esx == 0) {
|
|
--hx;
|
|
} else {
|
|
esx -= 1;
|
|
hx = hx - 1;
|
|
if (esx > 0)
|
|
hx |= 0x80000000;
|
|
}
|
|
} else
|
|
hx -= 1;
|
|
}
|
|
lx -= 1;
|
|
} else { /* x < y, x += ulp */
|
|
lx += 1;
|
|
if(lx==0) {
|
|
hx += 1;
|
|
if (hx==0 || (esx == 0 && hx == 0x80000000)) {
|
|
esx += 1;
|
|
hx |= 0x80000000;
|
|
}
|
|
}
|
|
}
|
|
} 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 <= 0x80000000) {
|
|
esx -= 1;
|
|
hx = hx - 1;
|
|
if ((esx&0x7fff) > 0)
|
|
hx |= 0x80000000;
|
|
} else
|
|
hx -= 1;
|
|
}
|
|
lx -= 1;
|
|
} else { /* x > y, x += ulp */
|
|
lx += 1;
|
|
if(lx==0) {
|
|
hx += 1;
|
|
if (hx==0 || (esx == 0xffff8000 && hx == 0x80000000)) {
|
|
esx += 1;
|
|
hx |= 0x80000000;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
esy = esx&0x7fff;
|
|
if(esy==0x7fff) return x+x; /* overflow */
|
|
if(esy==0) { /* underflow */
|
|
y = x*x;
|
|
if(y!=x) { /* raise underflow flag */
|
|
SET_LDOUBLE_WORDS(y,esx,hx,lx);
|
|
return y;
|
|
}
|
|
}
|
|
SET_LDOUBLE_WORDS(x,esx,hx,lx);
|
|
return x;
|
|
}
|
|
weak_alias (__nextafterl, nextafterl)
|
|
strong_alias (__nextafterl, __nexttowardl)
|
|
weak_alias (__nextafterl, nexttowardl)
|