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1 /* @(#)w_exp.c 5.1 93/09/24 */
2 /*
3 * ====================================================
4 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
5 *
6 * Developed at SunPro, a Sun Microsystems, Inc. business.
7 * Permission to use, copy, modify, and distribute this
8 * software is freely granted, provided that this notice
9 * is preserved.
10 * ====================================================
11 */
12 #include <LibConfig.h>
13 #include <sys/EfiCdefs.h>
14 #if defined(LIBM_SCCS) && !defined(lint)
15 __RCSID("$NetBSD: w_exp.c,v 1.9 2002/05/26 22:02:00 wiz Exp $");
16 #endif
17
18 /*
19 * wrapper exp(x)
20 */
21
22 #include "math.h"
23 #include "math_private.h"
24
25 static const double
26 o_threshold= 7.09782712893383973096e+02, /* 0x40862E42, 0xFEFA39EF */
27 u_threshold= -7.45133219101941108420e+02; /* 0xc0874910, 0xD52D3051 */
28
29 double
30 exp(double x) /* wrapper exp */
31 {
32 #ifdef _IEEE_LIBM
33 return __ieee754_exp(x);
34 #else
35 double z;
36 z = __ieee754_exp(x);
37 if(_LIB_VERSION == _IEEE_) return z;
38 if(finite(x)) {
39 if(x>o_threshold)
40 return __kernel_standard(x,x,6); /* exp overflow */
41 else if(x<u_threshold)
42 return __kernel_standard(x,x,7); /* exp underflow */
43 }
44 return z;
45 #endif
46 }