57 lines
1.3 KiB
C
57 lines
1.3 KiB
C
|
/* w_expf.c -- float version of w_exp.c.
|
||
|
* 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.
|
||
|
* ====================================================
|
||
|
*/
|
||
|
|
||
|
#include <sys/cdefs.h>
|
||
|
#if defined(LIBM_SCCS) && !defined(lint)
|
||
|
__RCSID("$NetBSD: w_expf.c,v 1.7 2007/08/20 16:01:40 drochner Exp $");
|
||
|
#endif
|
||
|
|
||
|
/*
|
||
|
* wrapper expf(x)
|
||
|
*/
|
||
|
|
||
|
#include "namespace.h"
|
||
|
#include "math.h"
|
||
|
#include "math_private.h"
|
||
|
|
||
|
#ifdef __weak_alias
|
||
|
__weak_alias(expf, _expf)
|
||
|
#endif
|
||
|
|
||
|
static const float
|
||
|
o_threshold= 8.8721679688e+01, /* 0x42b17180 */
|
||
|
u_threshold= -1.0397208405e+02; /* 0xc2cff1b5 */
|
||
|
|
||
|
float
|
||
|
expf(float x) /* wrapper expf */
|
||
|
{
|
||
|
#ifdef _IEEE_LIBM
|
||
|
return __ieee754_expf(x);
|
||
|
#else
|
||
|
float z;
|
||
|
z = __ieee754_expf(x);
|
||
|
if(_LIB_VERSION == _IEEE_) return z;
|
||
|
if(finitef(x)) {
|
||
|
if(x>o_threshold)
|
||
|
/* exp overflow */
|
||
|
return (float)__kernel_standard((double)x,(double)x,106);
|
||
|
else if(x<u_threshold)
|
||
|
/* exp underflow */
|
||
|
return (float)__kernel_standard((double)x,(double)x,107);
|
||
|
}
|
||
|
return z;
|
||
|
#endif
|
||
|
}
|