Floating point numbers can have special values, such as infinite or NaN. With
the macro fpclassify(x) you can find out what type
x is. The macro takes any floating-point expression as argument. The
result takes one of the following values:
x is "Not a Number".
x is either plus or minus infinity.
x is zero.
x is too small to be represented in normalized
if nothing of the above is correct that it must be a normal
The other macros provide a short answer to some standard questions.