libm/w_exp2l.c

   1 /*
   2  * wrapper exp2l(x)
   3  */
   4
   5 #include <math.h>
   6 #include "math_private.h"
   7
   8 #if !defined __NO_LONG_DOUBLE_MATH
   9 long double
  10 exp2l (long double x)
  11 {
  12 # if defined(__UCLIBC_HAS_FENV__)
  13   long double z = (long double) pow(2.0, (double) x);
  14   if (__builtin_expect (!isfinite (z) || z == 0, 0)
  15       && isfinite (x) && _LIB_VERSION != _IEEE_)
  16     /* exp2 overflow: 244, exp2 underflow: 245 */
  17     return __kernel_standard_l (x, x, 244 + !!signbit (x));
  18
  19   return z;
  20 # else
  21   return (long double) pow(2.0, (double) x);
  22 # endif /* __UCLIBC_HAS_FENV__ */
  23 }
  24 #endif /* __NO_LONG_DOUBLE_MATH */