61 lines
1.5 KiB
C
61 lines
1.5 KiB
C
|
/*
|
||
|
|
* ====================================================
|
||
|
|
* 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.
|
||
|
|
* ====================================================
|
||
|
|
*/
|
||
|
|
|
||
|
|
#ifndef lint
|
||
|
|
static char rcsid[] = "$FreeBSD: src/lib/msun/src/s_nexttowardf.c,v 1.1 2005/03/07 04:57:38 das Exp $";
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#include <float.h>
|
||
|
|
|
||
|
|
#include "fpmath.h"
|
||
|
|
#include "math.h"
|
||
|
|
#include "math_private.h"
|
||
|
|
|
||
|
|
#define LDBL_INFNAN_EXP (LDBL_MAX_EXP * 2 - 1)
|
||
|
|
|
||
|
|
float
|
||
|
|
nexttowardf(float x, long double y)
|
||
|
|
{
|
||
|
|
union IEEEl2bits uy;
|
||
|
|
volatile float t;
|
||
|
|
int32_t hx,ix;
|
||
|
|
|
||
|
|
GET_FLOAT_WORD(hx,x);
|
||
|
|
ix = hx&0x7fffffff; /* |x| */
|
||
|
|
uy.e = y;
|
||
|
|
|
||
|
|
if((ix>0x7f800000) ||
|
||
|
|
(uy.bits.exp == LDBL_INFNAN_EXP &&
|
||
|
|
((uy.bits.manh&~LDBL_NBIT)|uy.bits.manl) != 0))
|
||
|
|
return x+y; /* x or y is nan */
|
||
|
|
if(x==y) return (float)y; /* x=y, return y */
|
||
|
|
if(ix==0) { /* x == 0 */
|
||
|
|
SET_FLOAT_WORD(x,(uy.bits.sign<<31)|1);/* return +-minsubnormal */
|
||
|
|
t = x*x;
|
||
|
|
if(t==x) return t; else return x; /* raise underflow flag */
|
||
|
|
}
|
||
|
|
if(hx>=0 ^ x < y) /* x -= ulp */
|
||
|
|
hx -= 1;
|
||
|
|
else /* x += ulp */
|
||
|
|
hx += 1;
|
||
|
|
ix = hx&0x7f800000;
|
||
|
|
if(ix>=0x7f800000) return x+x; /* overflow */
|
||
|
|
if(ix<0x00800000) { /* underflow */
|
||
|
|
t = x*x;
|
||
|
|
if(t!=x) { /* raise underflow flag */
|
||
|
|
SET_FLOAT_WORD(y,hx);
|
||
|
|
return y;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
SET_FLOAT_WORD(x,hx);
|
||
|
|
return x;
|
||
|
|
}
|