glibc/sysdeps/generic/w_log2.c
Jakub Jelinek 0ecb606cb6 2.5-18.1
2007-07-12 18:26:36 +00:00

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