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/* 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)
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