NAME
fpclassify —
classify real floating type
LIBRARY
library “libc”
SYNOPSIS
#include
<math.h>
int
fpclassify(real-floating
x);
DESCRIPTION
Thefpclassify()
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
STANDARDS
The fpclassify() macro conforms to
ISO/IEC 9899:1999
(“ISO C99”).