Implementation status: to be implemented


#include <math.h>

int fpclassify(real-floating x);


The fpclassify() macro classifies its argument value as NaN, infinite, normal, subnormal or zero. First, an argument represented in a format wider than its semantic type is converted to its semantic type. Then classification is based on the type of the argument.


x - a number to be classified.

Return value

The fpclassify() returns the value of the number classification macro appropriate to the value of its argument.


No errors are defined.

Implementation tasks

  • Complete math.h with following constants:
    FP_INFINITE (Positive or negative infinity (overflow))
    FP_NAN (Not-A-Number)
    FP_NORMAL (Normal value)
    FP_SUBNORMAL (Sub-normal value (underflow))
    FP_ZERO (Value of zero).
  • Implement the fpclassify().