ieee_funcs(3M) — Reliant UNIX 5.44c4

ieee_functions(3M)      (BSD Compatibility Package)      ieee_functions(3M)

NAME
     ieeefunctions, fpclass, isnan, copysign, scalbn - miscellaneous
     functions for IEEE arithmetic

SYNOPSIS
     /usr/ucb/cc [flag ...] file ... -lucb

     #include <fp.h>
     #include <math.h>
     #include <stdio.h>

     enum fpclasstype fpclass(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
     Standard 754-1985 or suggested in its appendix.

     fpclass(x) corresponds to the IEEE's class() and classifies x as
     zero, subnormal, normal, infinity, or quiet or signaling NaN;
     /usr/ucbinclude/sys/ieeefp.h defines enum fpclasstype. 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 multiplication.
     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





Page 1                       Reliant UNIX 5.44                Printed 11/98
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