src/port/rint.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * rint.c
   4  *        rint() implementation
   5  *
   6  * Copyright (c) 1999, repas AEG Automation GmbH
   7  *
   8  *
   9  * IDENTIFICATION
  10  *        $PostgreSQL$
  11  *
  12  *-------------------------------------------------------------------------
  13  */
  14
  15 #include "c.h"
  16 #include <math.h>
  17
  18 double
  19 rint(double x)
  20 {
  21         double          f,
  22                                 n = 0.;
  23
  24         f = modf(x, &n);
  25
  26         if (x > 0.)
  27         {
  28                 if (f > .5)
  29                         n += 1.;
  30         }
  31         else if (x < 0.)
  32         {
  33                 if (f < -.5)
  34                         n -= 1.;
  35         }
  36         return n;
  37 }