glibc/sysdeps/ieee754/ldbl-128/s_nextafterl.c
Joseph Myers 85422c2acb Make nextafter, nexttoward set errno (bug 6799).
nextafter and nexttoward fail to set errno on overflow and underflow.
This patch makes them do so in cases that should include all the cases
where such errno setting is required by glibc's goals for when to set
errno (but not all cases of underflow where the result is nonzero and
so glibc's goals do not require errno setting).

Tested for x86_64, x86, mips64 and powerpc.

	[BZ #6799]
	* math/s_nextafter.c: Include <errno.h>.
	(__nextafter): Set errno on overflow and underflow.
	* math/s_nexttowardf.c: Include <errno.h>.
	(__nexttowardf): Set errno on overflow and underflow.
	* sysdeps/i386/fpu/s_nextafterl.c: Include <errno.h>.
	(__nextafterl): Set errno on overflow and underflow.
	* sysdeps/i386/fpu/s_nexttoward.c: Include <errno.h>.
	(__nexttoward): Set errno on overflow and underflow.
	* sysdeps/i386/fpu/s_nexttowardf.c: Include <errno.h>.
	(__nexttowardf): Set errno on overflow and underflow.
	* sysdeps/ieee754/flt-32/s_nextafterf.c: Include <errno.h>.
	(__nextafterf): Set errno on overflow and underflow.
	* sysdeps/ieee754/ldbl-128/s_nextafterl.c: Include <errno.h>.
	(__nextafterl): Set errno on overflow and underflow.
	* sysdeps/ieee754/ldbl-128/s_nexttoward.c: Include <errno.h>.
	(__nexttoward): Set errno on overflow and underflow.
	* sysdeps/ieee754/ldbl-128/s_nexttowardf.c: Include <errno.h>.
	(__nexttowardf): Set errno on overflow and underflow.
	* sysdeps/ieee754/ldbl-128ibm/s_nextafterl.c: Include <errno.h>.
	(__nextafterl): Set errno on overflow and underflow.
	* sysdeps/ieee754/ldbl-128ibm/s_nexttoward.c: Include <errno.h>.
	(__nexttoward): Set errno on overflow and underflow.
	* sysdeps/ieee754/ldbl-128ibm/s_nexttowardf.c: Include <errno.h>.
	(__nexttowardf): Set errno on overflow and underflow.
	* sysdeps/ieee754/ldbl-96/s_nexttoward.c: Include <errno.h>.
	(__nexttoward): Set errno on overflow and underflow.
	* sysdeps/ieee754/ldbl-96/s_nexttowardf.c: Include <errno.h>.
	(__nexttowardf): Set errno on overflow and underflow.
	* sysdeps/ieee754/ldbl-opt/s_nexttowardfd.c: Include <errno.h>.
	(__nldbl_nexttowardf): Set errno on overflow and underflow.
	* sysdeps/m68k/m680x0/fpu/s_nextafterl.c: Include <errno.h>.
	(__nextafterl): Set errno on overflow and underflow.
	* math/libm-test.inc (nextafter_test_data): Do not allow errno
	setting to be missing on overflow.  Add more tests.
	(nexttoward_test_data): Likewise.
2015-11-02 18:54:19 +00:00

87 lines
2.3 KiB
C

/* s_nextafterl.c -- long double version of s_nextafter.c.
* Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz.
*/
/*
* ====================================================
* 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 <errno.h>
#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 */
long double u;
SET_LDOUBLE_WORDS64(x,hy&0x8000000000000000ULL,1);/* return +-minsubnormal */
u = math_opt_barrier (x);
u = u * u;
math_force_eval (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) {
long double u = x + x; /* overflow */
math_force_eval (u);
__set_errno (ERANGE);
}
if(hy==0) {
long double u = x*x; /* underflow */
math_force_eval (u); /* raise underflow flag */
__set_errno (ERANGE);
}
SET_LDOUBLE_WORDS64(x,hx,lx);
return x;
}
weak_alias (__nextafterl, nextafterl)
strong_alias (__nextafterl, __nexttowardl)
weak_alias (__nextafterl, nexttowardl)