Intel® Fortran Compiler 18.0 Developer Guide and Reference
Inquiry Module Intrinsic Function (Generic): Returns whether the processor supports IEEE Not-a-Number feature.
USE, INTRINSIC :: IEEE_ARITHMETIC
result = IEEE_SUPPORT_NAN ([x])
x |
(Input; optional) Must be of type REAL; it can be scalar or array valued. |
The result is a scalar of type default logical. If x is omitted, the result has the value true if the processor supports NaNs for all real values; otherwise, false.
If x is specified, the result has the value true if the processor supports NaNs for real variables of the same kind type parameter as x; otherwise, false.
IEEE_SUPPORT_NAN () has the value true if IEEE NaNs are supported for all real types.