ilogb, ilogbf : get exponent of floating point number

Synopsis

#include <math.h>
int ilogb(double val);
int ilogbf(float val);
```### Description

All non zero, normal numbers can be described as m * 2**p. ilogb and ilogbf examine the argument val, and return p. The functions frexp and frexpf are similar to ilogb and ilogbf, but also return m.### Returns

ilogb and ilogbf return the power of two used to form the floating point argument. If val is 0, they return - INT_MAX (INT_MAX is defined in limits.h). If val is infinite, or NaN, they return INT_MAX.

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**Authoritative source**: BUSMASTER DITA help source `ilogb.dita`, compiled into `BUSMASTER.CHM` with the application.