LOGB(3) | Library Functions Manual | LOGB(3) |
logb
— return
exponent as a floating-point number
#include
<math.h>
double
logb
(double
x);
long double
logbl
(long
double x);
float
logbf
(float
x);
The
logb
()
functions return the exponent of x, represented as a floating-point
number.
logb
(±0)
returns -infinity and raises the "divide-by-zero" floating-point
exception.
logb
(±infinity)
returns +infinity.
If you need to apply the logb
() functions
to SIMD vectors or arrays, using the following functions provided by the
Accelerate.framework may give significantly better performance:
#include
<Accelerate/Accelerate.h>
vFloat
vlogbf
(vFloat
x);
void
vvlogbf
(float
*y, const float *x, const int
*n);
void
vvlogb
(double
*y, const double *x, const int
*n);
The logb
() functions conform to ISO/IEC
9899:2011.
August 21, 2012 | macOS 14.6 |