LOGB(3) BSD Library Functions Manual LOGB(3)NAMElogb — return exponent as a floating-point number
SYNOPSIS
#include <math.h>
double
logb(double x);
long double
logbl(long double x);
float
logbf(float x);
DESCRIPTION
The logb() functions return the exponent of x, represented as a floating-
point number.
SPECIAL VALUES
logb(�0) returns -infinity and raises the "divide-by-zero" floating-point
exception.
logb(�infinity) returns +infinity.
VECTOR OPERATIONS
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);
SEE ALSOilogb(3)log(3)math(3)STANDARDS
The logb() functions conform to ISO/IEC 9899:2011.
BSD August 21, 2012 BSD