src/port/isinf.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * isinf.c
   4  *
   5  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
   6  * Portions Copyright (c) 1994, Regents of the University of California
   7  *
   8  *
   9  * IDENTIFICATION
  10  *        $PostgreSQL$
  11  *
  12  *-------------------------------------------------------------------------
  13  */
  14
  15 #include "c.h"
  16
  17 #include <float.h>
  18 #include <math.h>
  19
  20 #if HAVE_FPCLASS                                /* this is _not_ HAVE_FP_CLASS, and not typo */
  21
  22 #if HAVE_IEEEFP_H
  23 #include <ieeefp.h>
  24 #endif
  25 int
  26 isinf(double d)
  27 {
  28         fpclass_t       type = fpclass(d);
  29
  30         switch (type)
  31         {
  32                 case FP_NINF:
  33                 case FP_PINF:
  34                         return 1;
  35                 default:
  36                         break;
  37         }
  38         return 0;
  39 }
  40 #else
  41
  42 #if defined(HAVE_FP_CLASS) || defined(HAVE_FP_CLASS_D)
  43
  44 #if HAVE_FP_CLASS_H
  45 #include <fp_class.h>
  46 #endif
  47 int
  48 isinf(x)
  49 double          x;
  50 {
  51 #if HAVE_FP_CLASS
  52         int                     fpclass = fp_class(x);
  53 #else
  54         int                     fpclass = fp_class_d(x);
  55 #endif
  56
  57         if (fpclass == FP_POS_INF)
  58                 return 1;
  59         if (fpclass == FP_NEG_INF)
  60                 return -1;
  61         return 0;
  62 }
  63 #elif defined(HAVE_CLASS)
  64 int
  65 isinf(double x)
  66 {
  67         int                     fpclass = class(x);
  68
  69         if (fpclass == FP_PLUS_INF)
  70                 return 1;
  71         if (fpclass == FP_MINUS_INF)
  72                 return -1;
  73         return 0;
  74 }
  75 #endif
  76
  77 #endif