math/w_exp2_compat.c

   1 /*
   2  * wrapper exp2(x)
   3  */
   4
   5 #include <math.h>
   6 #include <math_private.h>
   7 #include <math-svid-compat.h>
   8 #include <libm-alias-double.h>
   9
  10 #if LIBM_SVID_COMPAT
  11 double
  12 __exp2 (double x)
  13 {
  14   double z = __ieee754_exp2 (x);
  15   if (__builtin_expect (!isfinite (z) || z == 0, 0)
  16       && isfinite (x) && _LIB_VERSION != _IEEE_)
  17     /* exp2 overflow: 44, exp2 underflow: 45 */
  18     return __kernel_standard (x, x, 44 + !!signbit (x));
  19
  20   return z;
  21 }
  22 libm_alias_double (__exp2, exp2)
  23 #endif