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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.
STANDARDS
The fpclassify() macro conforms to ISO/IEC 9899:1999 (“ISO C99”).