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LOGB(3)                  BSD Library Functions Manual                  LOGB(3)

NAME
     logb -- 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(+-_) 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 pro-vided provided
     vided 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 ALSO
     ilogb (3) журнал (3) математика (3)

STANDARDS
     The logb() functions conform to ISO/IEC 9899:2011.

BSD                             August 21, 2012                            BSD