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ISNORMAL(3) |
Library Functions Manual |
ISNORMAL(3) |
NAME
isnormal — test for normal value
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <math.h>
int
isnormal(real-floating x);
DESCRIPTION
The
isnormal() macro determines whether its argument
x has a normal value. An argument represented in a format wider than its semantic type is converted to its semantic type first. The determination is then based on the type of the argument.
IEEE 754
It is determined whether the value of x is normal, and neither zero, subnormal, infinite nor NaN.
VAX
It is determined whether the value of x is finite, and neither true zero, dirty zero nor ROP.
RETURN VALUES
The isnormal() macro returns a non-zero value if the value of x is finite. Otherwise 0 is returned.
ERRORS
No errors are defined.
STANDARDS
The isnormal() macro conforms to ISO/IEC 9899:1999 (“ISO C99”).