libjava/classpath/native/fdlibm/w_exp.c

   1
   2 /* @(#)w_exp.c 1.4 04/04/22 */
   3 /*
   4  * ====================================================
   5  * Copyright (C) 2004 by Sun Microsystems, Inc. All rights reserved.
   6  *
   7  * Permission to use, copy, modify, and distribute this
   8  * software is freely granted, provided that this notice
   9  * is preserved.
  10  * ====================================================
  11  */
  12
  13 /*
  14  * wrapper exp(x)
  15  */
  16
  17 #include "fdlibm.h"
  18
  19 #ifdef __STDC__
  20 static const double
  21 #else
  22 static double
  23 #endif
  24 o_threshold=  7.09782712893383973096e+02,  /* 0x40862E42, 0xFEFA39EF */
  25 u_threshold= -7.45133219101941108420e+02;  /* 0xc0874910, 0xD52D3051 */
  26
  27 #ifdef __STDC__
  28         double exp(double x)            /* wrapper exp */
  29 #else
  30         double exp(x)                   /* wrapper exp */
  31         double x;
  32 #endif
  33 {
  34 #ifdef _IEEE_LIBM
  35         return __ieee754_exp(x);
  36 #else
  37         double z;
  38         z = __ieee754_exp(x);
  39         if(_LIB_VERSION == _IEEE_) return z;
  40         if(finite(x)) {
  41             if(x>o_threshold)
  42                 return __kernel_standard(x,x,6); /* exp overflow */
  43             else if(x<u_threshold)
  44                 return __kernel_standard(x,x,7); /* exp underflow */
  45         }
  46         return z;
  47 #endif
  48 }