ieee_functions(3M) MATHEMATICAL LIBRARY ieee_functions(3M)
NAME
ieee_functions, fp_class, isnan, copysign, scalbn - miscel-
laneous functions for IEEE arithmetic
SYNOPSIS
cc [ flag... ] file ... -lucb
#include <fp.h>
#include <math.h>
#include <stdio.h>
enum fp_class_type fp_class(x)
double x;
int isnan(x)
double x;
double copysign(x,y)
double x, y;
double scalbn(x,n)
double x; int n;
DESCRIPTION
Most of these functions provide capabilities required by
ANSI/IEEE Std 754-1985 or suggested in its appendix.
fp_class(x) corresponds to the IEEE's class() and classifies
x as zero, subnormal, normal, oo, or quiet or signaling NaN;
/usr/ucbinclude/sys/ieeefp.h defines enum fp_class_type.
The following function returns 0 if the indicated condition
is not satisfied:
isnan(x) returns 1 if x is NaN
copysign(x,y) returns x with y's sign bit. scalbn(x,n)
returns x* 2**n computed by exponent manipulation rather
than by actually performing an exponentiation or a multipli-
cation. Thus
1 _ scalbn(fabs(x),-ilogb(x)) < 2 for every x except 0,
infinity, and NaN.
FILES
/usr/ucbinclude/sys/ieeefp.h
/usr/ucbinclude/math.h
/usr/include/values.h
Last change: BSD Compatibility Package 1