33 lines
576 B
C
33 lines
576 B
C
/*
|
|
* wrapper log2(X)
|
|
*/
|
|
|
|
#include <math.h>
|
|
#include "math_private.h"
|
|
|
|
double
|
|
__log2 (double x) /* wrapper log2 */
|
|
{
|
|
#ifdef _IEEE_LIBM
|
|
return __ieee754_log2 (x);
|
|
#else
|
|
double z;
|
|
z = __ieee754_log2 (x);
|
|
if (_LIB_VERSION == _IEEE_ || __isnan (x)) return z;
|
|
if (x <= 0.0)
|
|
{
|
|
if (x == 0.0)
|
|
return __kernel_standard (x, x, 48); /* log2 (0) */
|
|
else
|
|
return __kernel_standard (x, x, 49); /* log2 (x < 0) */
|
|
}
|
|
else
|
|
return z;
|
|
#endif
|
|
}
|
|
weak_alias (__log2, log2)
|
|
#ifdef NO_LONG_DOUBLE
|
|
strong_alias (__log2, __log2l)
|
|
weak_alias (__log2, log2l)
|
|
#endif
|