mirror of
git://sourceware.org/git/glibc.git
synced 2024-11-21 01:12:26 +08:00
31 lines
537 B
C
31 lines
537 B
C
/*
|
|
* wrapper log2(X)
|
|
*/
|
|
|
|
#include <math.h>
|
|
#include "math_private.h"
|
|
|
|
float
|
|
__log2f (float x) /* wrapper log2f */
|
|
{
|
|
#ifdef _IEEE_LIBM
|
|
return __ieee754_log2f (x);
|
|
#else
|
|
float z;
|
|
z = __ieee754_log2f (x);
|
|
if (_LIB_VERSION == _IEEE_ || __isnanf (x)) return z;
|
|
if (x <= 0.0f)
|
|
{
|
|
if (x == 0.0f)
|
|
/* log2f (0) */
|
|
return __kernel_standard ((double) x, (double) x, 148);
|
|
else
|
|
/* log2f (x < 0) */
|
|
return __kernel_standard ((double) x, (double) x, 149);
|
|
}
|
|
else
|
|
return z;
|
|
#endif
|
|
}
|
|
weak_alias (__log2f, log2f)
|