1*2fe8fb19SBen Gras /* @(#)w_exp.c 5.1 93/09/24 */
2*2fe8fb19SBen Gras /*
3*2fe8fb19SBen Gras * ====================================================
4*2fe8fb19SBen Gras * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
5*2fe8fb19SBen Gras *
6*2fe8fb19SBen Gras * Developed at SunPro, a Sun Microsystems, Inc. business.
7*2fe8fb19SBen Gras * Permission to use, copy, modify, and distribute this
8*2fe8fb19SBen Gras * software is freely granted, provided that this notice
9*2fe8fb19SBen Gras * is preserved.
10*2fe8fb19SBen Gras * ====================================================
11*2fe8fb19SBen Gras */
12*2fe8fb19SBen Gras
13*2fe8fb19SBen Gras #include <sys/cdefs.h>
14*2fe8fb19SBen Gras #if defined(LIBM_SCCS) && !defined(lint)
15*2fe8fb19SBen Gras __RCSID("$NetBSD: w_exp.c,v 1.10 2007/08/20 16:01:40 drochner Exp $");
16*2fe8fb19SBen Gras #endif
17*2fe8fb19SBen Gras
18*2fe8fb19SBen Gras /*
19*2fe8fb19SBen Gras * wrapper exp(x)
20*2fe8fb19SBen Gras */
21*2fe8fb19SBen Gras
22*2fe8fb19SBen Gras #include "namespace.h"
23*2fe8fb19SBen Gras #include "math.h"
24*2fe8fb19SBen Gras #include "math_private.h"
25*2fe8fb19SBen Gras
26*2fe8fb19SBen Gras #ifdef __weak_alias
27*2fe8fb19SBen Gras __weak_alias(exp, _exp)
28*2fe8fb19SBen Gras #endif
29*2fe8fb19SBen Gras
30*2fe8fb19SBen Gras static const double
31*2fe8fb19SBen Gras o_threshold= 7.09782712893383973096e+02, /* 0x40862E42, 0xFEFA39EF */
32*2fe8fb19SBen Gras u_threshold= -7.45133219101941108420e+02; /* 0xc0874910, 0xD52D3051 */
33*2fe8fb19SBen Gras
34*2fe8fb19SBen Gras double
exp(double x)35*2fe8fb19SBen Gras exp(double x) /* wrapper exp */
36*2fe8fb19SBen Gras {
37*2fe8fb19SBen Gras #ifdef _IEEE_LIBM
38*2fe8fb19SBen Gras return __ieee754_exp(x);
39*2fe8fb19SBen Gras #else
40*2fe8fb19SBen Gras double z;
41*2fe8fb19SBen Gras z = __ieee754_exp(x);
42*2fe8fb19SBen Gras if(_LIB_VERSION == _IEEE_) return z;
43*2fe8fb19SBen Gras if(finite(x)) {
44*2fe8fb19SBen Gras if(x>o_threshold)
45*2fe8fb19SBen Gras return __kernel_standard(x,x,6); /* exp overflow */
46*2fe8fb19SBen Gras else if(x<u_threshold)
47*2fe8fb19SBen Gras return __kernel_standard(x,x,7); /* exp underflow */
48*2fe8fb19SBen Gras }
49*2fe8fb19SBen Gras return z;
50*2fe8fb19SBen Gras #endif
51*2fe8fb19SBen Gras }
52