math/w_log2f.c

   1 /*
   2  * wrapper log2(X)
   3  */
   4
   5 #include <math.h>
   6 #include "math_private.h"
   7
   8 float
   9 __log2f (float x)       /* wrapper log2f */
  10 {
  11 #ifdef _IEEE_LIBM
  12   return __ieee754_log2f (x);
  13 #else
  14   float z;
  15   z = __ieee754_log2f (x);
  16   if (_LIB_VERSION == _IEEE_ || __isnanf (x)) return z;
  17   if (x <= 0.0f)
  18     {
  19       if (x == 0.0f)
  20         /* log2f (0) */
  21         return __kernel_standard ((double) x, (double) x, 148);
  22       else
  23         /* log2f (x < 0) */
  24         return __kernel_standard ((double) x, (double) x, 149);
  25     }
  26   else
  27     return z;
  28 #endif
  29 }
  30 weak_alias (__log2f, log2f)