isnormal() — Determines if X is normal

Standards

Standards / Extensions	C or C++	Dependencies
C99 Single UNIX Specification, Version 3 C/C++ DFP C++ TR1 C99	both	z/OS V1R8

Format

#define _ISOC99_SOURCE
#include <math.h>

int isnormal(real-floating x);

#define __STDC_WANT_DEC_FP__
#include <math.h>

int isnormal(real-floating x);  /* C only */
int isnormal(decimal-floating x);  /* C only */
bool isnormal(real-floating x);  /* C++ only */
bool isnormal(decimal-floating x);  /* C++ only */

#define _TR1_C99
#include <math.h>

bool isnormal(real-floating x);  /* C++ only */

General description

The isnormal() macro or function template determines if its argument value is normal, that is, not zero, infinity, subnormal or a NaN.

Function	Hex	IEEE
isnormal	X	X

Notes:

To use IEEE decimal floating-point, the hardware must have the Decimal Floating-Point Facility installed.
This function works in IEEE decimal floating-point format. See "IEEE Decimal Floating-Point" for more information.

Returned value

The isnormal() macro returns 1 if the argument value is normal, else returns 0. The C++ template returns true if the argument value is normal, else returns false.

Special behavior in Hex: For normalized numbers, isnormal() returns one. For zero or an unnormalized number, isnormal() returns zero. The C++ function template for normalized numbers, isnormal() returns true. For zero or a number that is not normalized, isnormal() returns false.

Related information

math.h