audk/StdLib/LibC/Math/w_exp.c

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/* @(#)w_exp.c 5.1 93/09/24 */
/*
* ====================================================
* 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 <LibConfig.h>
#include <sys/EfiCdefs.h>
#if defined(LIBM_SCCS) && !defined(lint)
__RCSID("$NetBSD: w_exp.c,v 1.9 2002/05/26 22:02:00 wiz Exp $");
#endif
/*
* wrapper exp(x)
*/
#include "math.h"
#include "math_private.h"
static const double
o_threshold= 7.09782712893383973096e+02, /* 0x40862E42, 0xFEFA39EF */
u_threshold= -7.45133219101941108420e+02; /* 0xc0874910, 0xD52D3051 */
double
exp(double x) /* wrapper exp */
{
#ifdef _IEEE_LIBM
return __ieee754_exp(x);
#else
double z;
z = __ieee754_exp(x);
if(_LIB_VERSION == _IEEE_) return z;
if(finite(x)) {
if(x>o_threshold)
return __kernel_standard(x,x,6); /* exp overflow */
else if(x<u_threshold)
return __kernel_standard(x,x,7); /* exp underflow */
}
return z;
#endif
}