sysdeps/unix/sysv/aix/uitrunc.c

   1 /* Copyright (C) 2000 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <math.h>
  20
  21 /* The uitrunc function returns the nearest unsigned integer
  22    to the x parameter in the direction of 0. This actions is
  23    equivalent to truncation off the fraction bits of the x
  24    parameter and then converting x to an unsigned integer. */
  25 unsigned int
  26 __uitrunc (double x)
  27 {
  28   double xrf;
  29   unsigned int xr;
  30   xr = (unsigned int) x;
  31   xrf = (double) xr;
  32   if (x >= 0.0)
  33     if (x - xrf >= 0.5 && x - xrf < 1.0 && x + 1 > 0)
  34       return x + 1;
  35     else
  36       return x;
  37   else
  38     if (xrf - x >= 0.5 && xrf - x < 1.0 && x - 1 < 0)
  39       return x - 1;
  40     else
  41       return x;
  42 }