/* sf_nextafter.c -- float version of s_nextafter.c.
|
/* sf_nextafter.c -- float version of s_nextafter.c.
|
* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
|
* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
|
*/
|
*/
|
|
|
/*
|
/*
|
* ====================================================
|
* ====================================================
|
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
|
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
|
*
|
*
|
* Developed at SunPro, a Sun Microsystems, Inc. business.
|
* Developed at SunPro, a Sun Microsystems, Inc. business.
|
* Permission to use, copy, modify, and distribute this
|
* Permission to use, copy, modify, and distribute this
|
* software is freely granted, provided that this notice
|
* software is freely granted, provided that this notice
|
* is preserved.
|
* is preserved.
|
* ====================================================
|
* ====================================================
|
*/
|
*/
|
|
|
#include "fdlibm.h"
|
#include "fdlibm.h"
|
|
|
#ifdef __STDC__
|
#ifdef __STDC__
|
float nextafterf(float x, float y)
|
float nextafterf(float x, float y)
|
#else
|
#else
|
float nextafterf(x,y)
|
float nextafterf(x,y)
|
float x,y;
|
float x,y;
|
#endif
|
#endif
|
{
|
{
|
__int32_t hx,hy,ix,iy;
|
__int32_t hx,hy,ix,iy;
|
|
|
GET_FLOAT_WORD(hx,x);
|
GET_FLOAT_WORD(hx,x);
|
GET_FLOAT_WORD(hy,y);
|
GET_FLOAT_WORD(hy,y);
|
ix = hx&0x7fffffff; /* |x| */
|
ix = hx&0x7fffffff; /* |x| */
|
iy = hy&0x7fffffff; /* |y| */
|
iy = hy&0x7fffffff; /* |y| */
|
|
|
if(FLT_UWORD_IS_NAN(ix) ||
|
if(FLT_UWORD_IS_NAN(ix) ||
|
FLT_UWORD_IS_NAN(iy))
|
FLT_UWORD_IS_NAN(iy))
|
return x+y;
|
return x+y;
|
if(x==y) return x; /* x=y, return x */
|
if(x==y) return x; /* x=y, return x */
|
if(FLT_UWORD_IS_ZERO(ix)) { /* x == 0 */
|
if(FLT_UWORD_IS_ZERO(ix)) { /* x == 0 */
|
SET_FLOAT_WORD(x,(hy&0x80000000)|FLT_UWORD_MIN);
|
SET_FLOAT_WORD(x,(hy&0x80000000)|FLT_UWORD_MIN);
|
y = x*x;
|
y = x*x;
|
if(y==x) return y; else return x; /* raise underflow flag */
|
if(y==x) return y; else return x; /* raise underflow flag */
|
}
|
}
|
if(hx>=0) { /* x > 0 */
|
if(hx>=0) { /* x > 0 */
|
if(hx>hy) { /* x > y, x -= ulp */
|
if(hx>hy) { /* x > y, x -= ulp */
|
hx -= 1;
|
hx -= 1;
|
} else { /* x < y, x += ulp */
|
} else { /* x < y, x += ulp */
|
hx += 1;
|
hx += 1;
|
}
|
}
|
} else { /* x < 0 */
|
} else { /* x < 0 */
|
if(hy>=0||hx>hy){ /* x < y, x -= ulp */
|
if(hy>=0||hx>hy){ /* x < y, x -= ulp */
|
hx -= 1;
|
hx -= 1;
|
} else { /* x > y, x += ulp */
|
} else { /* x > y, x += ulp */
|
hx += 1;
|
hx += 1;
|
}
|
}
|
}
|
}
|
hy = hx&0x7f800000;
|
hy = hx&0x7f800000;
|
if(hy>FLT_UWORD_MAX) return x+x; /* overflow */
|
if(hy>FLT_UWORD_MAX) return x+x; /* overflow */
|
if(hy<0x00800000) { /* underflow */
|
if(hy<0x00800000) { /* underflow */
|
y = x*x;
|
y = x*x;
|
if(y!=x) { /* raise underflow flag */
|
if(y!=x) { /* raise underflow flag */
|
SET_FLOAT_WORD(y,hx);
|
SET_FLOAT_WORD(y,hx);
|
return y;
|
return y;
|
}
|
}
|
}
|
}
|
SET_FLOAT_WORD(x,hx);
|
SET_FLOAT_WORD(x,hx);
|
return x;
|
return x;
|
}
|
}
|
|
|
#ifdef _DOUBLE_IS_32BITS
|
#ifdef _DOUBLE_IS_32BITS
|
|
|
#ifdef __STDC__
|
#ifdef __STDC__
|
double nextafter(double x, double y)
|
double nextafter(double x, double y)
|
#else
|
#else
|
double nextafter(x,y)
|
double nextafter(x,y)
|
double x,y;
|
double x,y;
|
#endif
|
#endif
|
{
|
{
|
return (double) nextafterf((float) x, (float) x);
|
return (double) nextafterf((float) x, (float) x);
|
}
|
}
|
|
|
#endif /* defined(_DOUBLE_IS_32BITS) */
|
#endif /* defined(_DOUBLE_IS_32BITS) */
|
|
|
