sysdeps/alpha/fpu/s_nearbyintf.c

   1 /* Copyright (C) 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 #ifdef _IEEE_FP_INEXACT
  23 #error "Don't compile with -mieee-with-inexact"
  24 #endif
  25
  26 float
  27 __nearbyintf (float x)
  28 {
  29   float two23 = copysignf (0x1.0p23, x);
  30   float r;
  31
  32   r = x + two23;
  33   r = r - two23;
  34
  35   /* nearbyint(-0.1) == -0, and in general we'll always have the same sign
  36      as our input.  */
  37   return copysign (r, x);
  38 }
  39
  40 weak_alias (__nearbyintf, nearbyintf)