FPCLASSIFY(3) Library Functions Manual FPCLASSIFY(3)

NAME

fpclassifyclassify real floating type

LIBRARY

Standard C Library (libc, -lc)

SYNOPSIS

#include <math.h>

int
fpclassify(real-floating x);

DESCRIPTION

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.

IEEE 754

FP_INFINITE
infinity, either positive or negative
FP_NAN
not-a-number (“NaN”)
FP_NORMAL
normal
FP_SUBNORMAL
subnormal
FP_ZERO
zero

VAX

FP_ROP
reserved operand (“ROP”)
FP_DIRTYZERO
dirty zero
FP_NORMAL
finite
FP_ZERO
true zero

RETURN VALUES

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

ERRORS

No errors are defined.

SEE ALSO

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

STANDARDS

The fpclassify() macro conforms to ISO/IEC 9899:1999 (“ISO C99”).
January 14, 2004 NetBSD 6.1