sysdeps/alpha/fpu/s_rintf.c

   1 /* Copyright (C) 2000, 2007 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Richard Henderson.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <math.h>
  21
  22
  23 float
  24 __rintf (float x)
  25 {
  26   float two23 = copysignf (0x1.0p23, x);
  27   float r;
  28
  29   r = x + two23;
  30   r = r - two23;
  31
  32   /* rint(-0.1) == -0, and in general we'll always have the same sign
  33      as our input.  */
  34   return copysign (r, x);
  35 }
  36
  37 weak_alias (__rintf, rintf)