src/MSL_C.PPCEABI.bare.H/w_exp.c


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49


/* @(#)w_exp.c 1.2 95/01/04 */
/*
 * ====================================================
 * 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.
 * ====================================================
 */

/*
 * wrapper exp(x)
 */

#include "fdlibm.h"

#ifdef __STDC__
static const double
#else
static double
#endif
    o_threshold = 7.09782712893383973096e+02,  /* 0x40862E42, 0xFEFA39EF */
    u_threshold = -7.45133219101941108420e+02; /* 0xc0874910, 0xD52D3051 */

#ifdef __STDC__
double exp(double x) /* wrapper pow */
#else
double exp(x) /* wrapper exp */
double x;
#endif
{
#ifdef _IEEE_LIBM
  return __ieee754_exp(x);
#else
  double z;
  z = __ieee754_exp(x);
  if (_LIB_VERSION == _IEEE_)
    return z;
  if (isfinite(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
}