Intel® Fortran Compiler 18.0 Developer Guide and Reference
Elemental Module Intrinsic Function (Generic): Returns whether an IEEE value is Not-a-Number (NaN).
USE, INTRINSIC :: IEEE_ARITHMETIC
result = IEEE_IS_NAN (x)
x |
(Input) Must be of type REAL. |
The result type is default logical. The result has the value true if the value of x is NaN; otherwise, false.
IEEE_IS_NAN (SQRT(-2.0)) has the value true if IEEE_SUPPORT_SQRT (2.0) has the value true.