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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