fpclassify(3M)fpclassify(3M)NAMEfpclassify() - floating-point value classification macro
The macro classifies its argument value as NaN, infinite, normalized,
denormalized, or zero. The argument must be of floating type, and
classification is based on the type of the argument. For HP Integrity
servers, the argument can be any floating type. For PA-RISC, the argu‐
ment must be either or
The macro, used in conjunction with the macro, replaces the and func‐
tions, which are obsolete and are no longer supported.
To use the macro, compile either with the default option or with the
and options. Make sure your program includes Link in the math library
by specifying on the compiler or linker command line.
The macro returns the value of the number classification macro appro‐
priate to the type and value of its argument.
The value returned is one of the following macros, which are defined in
Every possible argument value falls into one of these categories, so
this macro never results in an error.
The macro raises no exceptions.
No errors are defined.
Take certain actions if is either a denormalized value or zero:
SEE ALSOisfinite(3M), isinf(3M), isnan(3M), isnormal(3M), signbit(3M), math(5).