phunix/lib/libm/src/s_nextafterl.c
Lionel Sambuc 84d9c625bf Synchronize on NetBSD-CVS (2013/12/1 12:00:00 UTC)
- Fix for possible unset uid/gid in toproto
 - Fix for default mtree style
 - Update libelf
 - Importing libexecinfo
 - Resynchronize GCC, mpc, gmp, mpfr
 - build.sh: Replace params with show-params.
     This has been done as the make target has been renamed in the same
     way, while a new target named params has been added. This new
     target generates a file containing all the parameters, instead of
     printing it on the console.
 - Update test48 with new etc/services (Fix by Ben Gras <ben@minix3.org)
     get getservbyport() out of the inner loop

Change-Id: Ie6ad5226fa2621ff9f0dee8782ea48f9443d2091
2014-07-28 17:05:06 +02:00

105 lines
2.5 KiB
C

/* $NetBSD: s_nextafterl.c,v 1.4 2013/07/18 22:31:13 matt Exp $ */
/* @(#)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 <sys/cdefs.h>
__RCSID("$NetBSD: s_nextafterl.c,v 1.4 2013/07/18 22:31:13 matt Exp $");
#include <float.h>
#include <math.h>
#include <machine/ieee.h>
#ifdef __HAVE_LONG_DOUBLE
#ifdef EXT_EXP_INFNAN
#if LDBL_MAX_EXP != 0x4000
#error "Unsupported long double format"
#endif
#ifdef LDBL_IMPLICIT_NBIT
#define LDBL_NBIT 0
#endif
/*
* IEEE functions
* nextafterl(x,y)
* return the next machine floating-point number of x in the
* direction toward y.
* Special cases:
* If x == y, y shall be returned
* If x or y is NaN, a NaN shall be returned
*/
long double
nextafterl(long double x, long double y)
{
volatile long double t;
union ieee_ext_u ux, uy;
ux.extu_ld = x;
uy.extu_ld = y;
if ((ux.extu_exp == EXT_EXP_NAN &&
((ux.extu_frach &~ LDBL_NBIT)|ux.extu_fracl) != 0) ||
(uy.extu_exp == EXT_EXP_NAN &&
((uy.extu_frach &~ LDBL_NBIT)|uy.extu_fracl) != 0))
return x+y; /* x or y is nan */
if (x == y) return y; /* x=y, return y */
if (x == 0.0) {
ux.extu_frach = 0; /* return +-minsubnormal */
ux.extu_fracl = 1;
ux.extu_sign = uy.extu_sign;
t = ux.extu_ld * ux.extu_ld;
if (t == ux.extu_ld)
return t;
else
return ux.extu_ld; /* raise underflow flag */
}
if ((x>0.0) ^ (x<y)) { /* x -= ulp */
if (ux.extu_fracl == 0) {
if ((ux.extu_frach & ~LDBL_NBIT) == 0)
ux.extu_exp -= 1;
ux.extu_frach = (ux.extu_frach - 1) |
(ux.extu_frach & LDBL_NBIT);
}
ux.extu_fracl -= 1;
} else { /* x += ulp */
ux.extu_fracl += 1;
if (ux.extu_fracl == 0) {
ux.extu_frach = (ux.extu_frach + 1) |
(ux.extu_frach & LDBL_NBIT);
if ((ux.extu_frach & ~LDBL_NBIT) == 0)
ux.extu_exp += 1;
}
}
if (ux.extu_exp == EXT_EXP_INF)
return x+x; /* overflow */
if (ux.extu_exp == 0) { /* underflow */
#ifndef LDBL_IMPLICIT_NBIT
mask_nbit_l(ux);
#endif
t = ux.extu_ld * ux.extu_ld;
if (t != ux.extu_ld) /* raise underflow flag */
return ux.extu_ld;
}
return ux.extu_ld;
}
#endif
#endif /* __HAVE_LONG_DOUBLE */