The isfinite macro returns a non-zero value if and only if its argument has a finite (zero, subnormal, or normal) value. The isinf, isnan, and isnormal macros return non-zero if and only if x is an infinity, NaN, or a non-zero normalized number, respectively.
The symbol isnanf is provided as an alias to isnan for compatibility, and its use is deprecated. Similarly, finite and finitef are deprecated versions of isfinite.
