FPCLASSIFY(3)

FPCLASSIFY(3) | Library Functions Manual | FPCLASSIFY(3)

# NAME

fpclassify — classify 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 5.99