FPCLASS(3-BSD) RISC/os Reference Manual FPCLASS(3-BSD)
NAME
fp_class - classes of IEEE floating-point values
SYNOPSIS
#include <fpclass.h>
int fpclassd(double x);
int fpclassf(float x);
DESCRIPTION
These routines are used to determine the class of IEEE
floating-point values. They return one of the constants in
the file <fp_class.h> and never cause an exception even for
signaling NaN's. These routines are to implement the recom-
mended function class(x) in the appendix of the IEEE
754-1985 standard for binary floating-point arithmetic.
The constants in <fp_class.h> refer to the following classes
of values:
Constant Class
FP_SNAN Signaling NaN (Not-a-Number)
FP_QNAN Quiet NaN (Not-a-Number)
FP_POS_INF +oo (positive infinity)
FP_NEG_INF -oo (negative infinity)
FP_POS_NORM positive normalized non-zero
FP_NEG_NORM negative normalized non-zero
FP_POS_DENORM positive denormalized
FP_NEG_DENORM negative denormalized
FP_POS_ZERO +0.0 (positive zero)
FP_NEG_ZERO -0.0 (negative zero)
ALSO SEE
ANSI/IEEE Std 754-1985, IEEE Standard for Binary Floating-
Point Arithmetic
Printed 11/19/92 Page 1