libm/w_exp2f.c

   1 /*
   2  * wrapper exp2f(x)
   3  */
   4
   5 #include <math.h>
   6 #include "math_private.h"
   7
   8 float
   9 exp2f (float x)
  10 {
  11 #if defined(__UCLIBC_HAS_FENV__)
  12   float z = (float) pow(2.0, (double) x);
  13   if (__builtin_expect (!isfinite (z) || z == 0, 0)
  14       && isfinite (x) && _LIB_VERSION != _IEEE_)
  15     /* exp2 overflow: 144, exp2 underflow: 145 */
  16     return __kernel_standard_f (x, x, 144 + !!signbit (x));
  17
  18   return z;
  19 #else
  20   return (float) pow(2.0, (double) x);
  21 #endif
  22 }