isnormal — test for a normal value
#include <math.h>
int isnormal(real-floating x);
[CX] The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of POSIX.1-2024 defers to the ISO C standard.The isnormal() macro shall determine whether its argument value is normal (neither zero, subnormal, infinite, nor NaN). First, an argument represented in a format wider than its semantic type is converted to its semantic type. Then determination is based on the type of the argument.
The isnormal() macro shall return a non-zero value if and only if its argument has a normal value.
No errors are defined.
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fpclassify , isfinite , isinf , isnan , signbit
XBD <math.h>
First released in Issue 6. Derived from the ISO/IEC 9899:1999 standard.
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