HPUX fpclassify[3m]

 fpclassify(3M)                                               fpclassify(3M)





 NAME
      fpclassify(), fpclassifyf() - floating-point operand classification
      functions

 SYNOPSIS
      #include <math.h>

      int fpclassify(double x);

      int fpclassifyf(float x);

 DESCRIPTION
      fpclassify() and fpclassifyf() return a non-negative integer value
      that specifies the IEEE operand class to which the argument x belongs.
      The value returned is one of the following macros which are defined in
      <math.h>:

           #define FP_PLUS_NORM      0  /* Positive normalized */
           #define FP_MINUS_NORM     1  /* Negative normalized */
           #define FP_PLUS_ZERO      2  /* Positive zero */
           #define FP_MINUS_ZERO     3  /* Negative zero */
           #define FP_PLUS_INF       4  /* Positive infinity */
           #define FP_MINUS_INF      5  /* Negative infinity */
           #define FP_PLUS_DENORM    6  /* Positive denormalized */
           #define FP_MINUS_DENORM   7  /* Negative denormalized */
           #define FP_SNAN           8  /* Signalling NaN */
           #define FP_QNAN           9  /* Quiet NaN */

      Every possible argument value falls into one of these ten categories,
      so these functions never result in an error.

      fpclassifyf() is the float version of fpclassify().  Programs must be
      compiled in ANSI mode (with the -Aa option) in order to use this
      function; otherwise, the compiler promotes the float argument to
      double, and the function returns incorrect results.

 DEPENDENCIES
    Series 300/400
      fpclassify() and fpclassifyf() are not supported on Series 300/400
      systems.

    Series 700/800
      fpclassify() and fpclassifyf() are provided in the PA1.1 versions of
      the math library only.  The +DA1.1 option (default on Series 700
      systems) links in a PA1.1 version automatically.  A PA1.1 library can
      also be linked in explicitly.  For more information, see the HP-UX
      Floating-Point Guide.

      These functions are not specified by any standard.  However, they
      implement the class() function suggested in the "Recommended Functions
      and Predicates" appendix of the IEEE-754 floating-point standard.



 Hewlett-Packard Company            - 1 -     HP-UX Release 9.0: August 1992






 fpclassify(3M)                                               fpclassify(3M)





      Also, fpclassifyf() is named in accordance with the conventions
      specified in the
       "Future Library Directions" section of the ANSI C standard.

 SEE ALSO
      isnan(3M), isinf(3M), ieee(3M).
















































 Hewlett-Packard Company            - 2 -     HP-UX Release 9.0: August 1992