ieee_functionss(3M) — Dell System V Release 4 Issue 2.2



ieee_functions(3M) UNIX System V(BSD Compatibility Package)  ieee_functions(3M)


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

SYNOPSIS
      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 Std
      754-1985 or suggested in its appendix.

      fpclass(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 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








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