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”).