FPCLASSIFY(3) Library Functions Manual FPCLASSIFY(3)

fpclassify
classify real floating type

Standard C Library (libc, -lc)

#include <math.h>

int
fpclassify(real-floating x);

The fpclassify() macro performs classification of its argument x. An argument represented in a format wider than its semantic type is converted to its semantic type first. The classification is then based on the type of the argument.

infinity, either positive or negative
not-a-number (“NaN”)
normal
subnormal
zero

reserved operand (“ROP”)
dirty zero
finite
true zero

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

No errors are defined.

isfinite(3), isnormal(3), math(3), signbit(3)

The fpclassify() macro conforms to ISO/IEC 9899:1999 (“ISO C99”).
January 14, 2004 NetBSD 9.0