ilogb
, ilogbf
---get exponent of floating point number#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
.
Portability
Neither ilogb
nor ilogbf
is required by ANSI C or by
the System V Interface Definition (Issue 2).
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