80 lines
2.0 KiB
C
80 lines
2.0 KiB
C
/* s_nexttowardf.c -- float version of s_nextafter.c.
|
|
* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com
|
|
* and 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
|
|
|
|
#include <errno.h>
|
|
#include <math.h>
|
|
#include <math_private.h>
|
|
#include <math_ldbl_opt.h>
|
|
#include <float.h>
|
|
|
|
float __nexttowardf(float x, long double y)
|
|
{
|
|
int32_t hx,ix;
|
|
int64_t hy,iy;
|
|
double yhi;
|
|
|
|
GET_FLOAT_WORD(hx,x);
|
|
yhi = ldbl_high (y);
|
|
EXTRACT_WORDS64 (hy, yhi);
|
|
ix = hx&0x7fffffff; /* |x| */
|
|
iy = hy&0x7fffffffffffffffLL; /* |y| */
|
|
|
|
if((ix>0x7f800000) || /* x is nan */
|
|
(iy>0x7ff0000000000000LL))
|
|
/* y is nan */
|
|
return x+y;
|
|
if((long double) x==y) return y; /* x=y, return y */
|
|
if(ix==0) { /* x == 0 */
|
|
float u;
|
|
SET_FLOAT_WORD(x,(uint32_t)((hy>>32)&0x80000000)|1);/* return +-minsub*/
|
|
u = math_opt_barrier (x);
|
|
u = u * u;
|
|
math_force_eval (u); /* raise underflow flag */
|
|
return x;
|
|
}
|
|
if(hx>=0) { /* x > 0 */
|
|
if(x > y) { /* x -= ulp */
|
|
hx -= 1;
|
|
} else { /* x < y, x += ulp */
|
|
hx += 1;
|
|
}
|
|
} else { /* x < 0 */
|
|
if(x < y) { /* x -= ulp */
|
|
hx -= 1;
|
|
} else { /* x > y, x += ulp */
|
|
hx += 1;
|
|
}
|
|
}
|
|
hy = hx&0x7f800000;
|
|
if(hy>=0x7f800000) {
|
|
float u = x+x; /* overflow */
|
|
math_force_eval (u);
|
|
__set_errno (ERANGE);
|
|
}
|
|
if(hy<0x00800000) { /* underflow */
|
|
float u = x*x;
|
|
math_force_eval (u); /* raise underflow flag */
|
|
__set_errno (ERANGE);
|
|
}
|
|
SET_FLOAT_WORD(x,hx);
|
|
return x;
|
|
}
|
|
long_double_symbol (libm, __nexttowardf, nexttowardf);
|