glibc/math/s_nextafter.c
Ulrich Drepper 3e336a8754 [BZ #3306]
2007-03-27  Jakub Jelinek  <jakub@redhat.com>
	[BZ #3306]
	* math/math_private.h (math_opt_barrier, math_force_eval): Define.
	* sysdeps/i386/fpu/math_private.h: New file.
	* sysdeps/x86_64/fpu/math_private.h: New file.
	* math/s_nexttowardf.c (__nexttowardf): Use math_opt_barrier and
	math_force_eval macros.  Use "+m" constraint on asm rather than
	"=m" and "m".
	* math/s_nextafter.c (__nextafter): Likewise.
	* sysdeps/ieee754/ldbl-128ibm/s_nexttoward.c (__nexttoward):
	Likewise.
	* sysdeps/ieee754/flt-32/s_nextafterf.c (__nextafterf): Likewise.
	* sysdeps/ieee754/ldbl-128/s_nexttoward.c (__nexttoward): Likewise.
	* sysdeps/ieee754/ldbl-96/s_nexttoward.c (__nexttoward): Likewise.
	* sysdeps/i386/fpu/s_nextafterl.c (__nextafterl): Use
	math_opt_barrier and math_force_eval macros.
	* sysdeps/ieee754/ldbl-128/s_nextafterl.c (__nextafterl): Likewise.
	* sysdeps/ieee754/ldbl-96/s_nextafterl.c (__nextafterl): Likewise.
	* sysdeps/i386/fpu/s_nexttoward.c: Include float.h.
	(__nexttoward): Use math_opt_barrier and
	math_force_eval macros.  Use "+m" constraint on asm rather than
	"=m" and "m".  Only use asm to force double result if
	FLT_EVAL_METHOD is 2.
	* sysdeps/i386/fpu/s_nexttowardf.c: Include float.h.
	(__nexttowardf): Use math_opt_barrier and
	math_force_eval macros.  Use "+m" constraint on asm rather than
	"=m" and "m".  Only use asm to force double result if
	FLT_EVAL_METHOD is not 0.
	* sysdeps/ieee754/ldbl-128ibm/s_nexttowardf.c: Include float.h.
	(__nexttowardf): Use math_opt_barrier and
	math_force_eval macros.  If FLT_EVAL_METHOD is not 0, force
	x to float using asm.
	* sysdeps/ieee754/ldbl-opt/s_nexttowardfd.c: Include float.h.
	(__nldbl_nexttowardf): Use math_opt_barrier and
	math_force_eval macros.  If FLT_EVAL_METHOD is not 0, force
	x to float using asm.
	* sysdeps/ieee754/ldbl-96/s_nexttowardf.c: Include float.h.
	(__nexttowardf): Use math_opt_barrier and math_force_eval
	macros.  If FLT_EVAL_METHOD is not 0, force x to float using asm.
	* math/bug-nextafter.c (zero, inf): New variables.
	(main): Add new tests.
	* math/bug-nexttoward.c (zero, inf): New variables.
	(main): Add new tests.
2007-04-16 20:41:42 +00:00

101 lines
2.6 KiB
C

/* @(#)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.
* ====================================================
*/
#if defined(LIBM_SCCS) && !defined(lint)
static char rcsid[] = "$NetBSD: s_nextafter.c,v 1.8 1995/05/10 20:47:58 jtc Exp $";
#endif
/* IEEE functions
* nextafter(x,y)
* return the next machine floating-point number of x in the
* direction toward y.
* Special cases:
*/
/* Ugly hack so that the aliasing works. */
#define __nexttoward __internal___nexttoward
#define nexttoward __internal_nexttoward
#include <math.h>
#include <math_private.h>
#include <float.h>
#ifdef __STDC__
double __nextafter(double x, double y)
#else
double __nextafter(x,y)
double x,y;
#endif
{
int32_t hx,hy,ix,iy;
u_int32_t lx,ly;
EXTRACT_WORDS(hx,lx,x);
EXTRACT_WORDS(hy,ly,y);
ix = hx&0x7fffffff; /* |x| */
iy = hy&0x7fffffff; /* |y| */
if(((ix>=0x7ff00000)&&((ix-0x7ff00000)|lx)!=0) || /* x is nan */
((iy>=0x7ff00000)&&((iy-0x7ff00000)|ly)!=0)) /* y is nan */
return x+y;
if(x==y) return y; /* x=y, return y */
if((ix|lx)==0) { /* x == 0 */
double u;
INSERT_WORDS(x,hy&0x80000000,1); /* 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 -= 1;
lx -= 1;
} else { /* x < y, x += ulp */
lx += 1;
if(lx==0) hx += 1;
}
} else { /* x < 0 */
if(hy>=0||hx>hy||((hx==hy)&&(lx>ly))){/* x < y, x -= ulp */
if(lx==0) hx -= 1;
lx -= 1;
} else { /* x > y, x += ulp */
lx += 1;
if(lx==0) hx += 1;
}
}
hy = hx&0x7ff00000;
if(hy>=0x7ff00000) {
x = x+x; /* overflow */
if (FLT_EVAL_METHOD != 0 && FLT_EVAL_METHOD != 1)
asm ("" : "+m"(x));
return x; /* overflow */
}
if(hy<0x00100000) {
double u = x*x; /* underflow */
math_force_eval (u); /* raise underflow flag */
}
INSERT_WORDS(x,hx,lx);
return x;
}
weak_alias (__nextafter, nextafter)
#ifdef NO_LONG_DOUBLE
strong_alias (__nextafter, __nextafterl)
weak_alias (__nextafter, nextafterl)
strong_alias (__nextafter, __nexttowardl)
weak_alias (__nexttowardl, nexttowardl)
#undef __nexttoward
strong_alias (__nextafter, __nexttoward)
#undef nexttoward
weak_alias (__nextafter, nexttoward)
#endif