mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-16 18:10:11 +00:00
82 lines
2.2 KiB
C
82 lines
2.2 KiB
C
|
/* s_nexttowardf.c -- float version of s_nextafter.c.
|
||
|
|
* Special i387 version.
|
||
|
|
* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@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
|
||
|
|
|
||
|
|
#include "math.h"
|
||
|
|
#include "math_private.h"
|
||
|
|
|
||
|
|
#ifdef __STDC__
|
||
|
|
float __nexttowardf(float x, long double y)
|
||
|
|
#else
|
||
|
|
float __nexttowardf(x,y)
|
||
|
|
float x;
|
||
|
|
long double y;
|
||
|
|
#endif
|
||
|
|
{
|
||
|
|
int32_t hx,ix,iy;
|
||
|
|
u_int32_t hy,ly,esy;
|
||
|
|
|
||
|
|
GET_FLOAT_WORD(hx,x);
|
||
|
|
GET_LDOUBLE_WORDS(esy,hy,ly,y);
|
||
|
|
ix = hx&0x7fffffff; /* |x| */
|
||
|
|
iy = esy&0x7fff; /* |y| */
|
||
|
|
|
||
|
|
/* Intel's extended format has the normally implicit 1 explicit
|
||
|
|
present. Sigh! */
|
||
|
|
if((ix>0x7f800000) || /* x is nan */
|
||
|
|
(iy>=0x7fff&&(((hy&0x7fffffff)|ly)!=0))) /* y is nan */
|
||
|
|
return x+y;
|
||
|
|
if((long double) x==y) return y; /* x=y, return y */
|
||
|
|
if(ix==0) { /* x == 0 */
|
||
|
|
float x2;
|
||
|
|
SET_FLOAT_WORD(x,((esy&0x8000)<<16)|1);/* return +-minsub*/
|
||
|
|
x2 = x*x;
|
||
|
|
if(x2==x) return x2; else return x; /* raise underflow flag */
|
||
|
|
}
|
||
|
|
if(hx>=0) { /* x > 0 */
|
||
|
|
if(esy>=0x8000||((ix>>23)&0xff)>iy-0x3f80
|
||
|
|
|| (((ix>>23)&0xff)==iy-0x3f80
|
||
|
|
&& ((ix&0x7fffff)<<8)>(hy&0x7fffffff))) {/* x > y, x -= ulp */
|
||
|
|
hx -= 1;
|
||
|
|
} else { /* x < y, x += ulp */
|
||
|
|
hx += 1;
|
||
|
|
}
|
||
|
|
} else { /* x < 0 */
|
||
|
|
if(esy<0x8000||((ix>>23)&0xff)>iy-0x3f80
|
||
|
|
|| (((ix>>23)&0xff)==iy-0x3f80
|
||
|
|
&& ((ix&0x7fffff)<<8)>(hy&0x7fffffff))) {/* x < y, x -= ulp */
|
||
|
|
hx -= 1;
|
||
|
|
} else { /* x > y, x += ulp */
|
||
|
|
hx += 1;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
hy = hx&0x7f800000;
|
||
|
|
if(hy>=0x7f800000) return x+x; /* overflow */
|
||
|
|
if(hy<0x00800000) { /* underflow */
|
||
|
|
float x2 = x*x;
|
||
|
|
if(x2!=x) { /* raise underflow flag */
|
||
|
|
SET_FLOAT_WORD(x2,hx);
|
||
|
|
return x2;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
SET_FLOAT_WORD(x,hx);
|
||
|
|
return x;
|
||
|
|
}
|
||
|
|
weak_alias (__nexttowardf, nexttowardf)
|