sysdeps/arm/eabi/setfpucw.c

   1 /* Set the FPU control word.
   2    Copyright (C) 1996, 1997, 1999, 2005 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <math.h>
  20 #include <fpu_control.h>
  21
  22 #include <unistd.h>
  23 #include <ldsodefs.h>
  24 #include <dl-procinfo.h>
  25 #include <sysdep.h>
  26
  27 void
  28 __setfpucw (fpu_control_t set)
  29 {
  30   if (GLRO (dl_hwcap) & HWCAP_ARM_VFP)
  31     {
  32       fpu_control_t cw;
  33
  34       /* Fetch the current control word.  */
  35       _FPU_GETCW (cw);
  36
  37       /* Preserve the reserved bits, and set the rest as the user
  38          specified (or the default, if the user gave zero).  */
  39       cw &= _FPU_RESERVED;
  40       cw |= set & ~_FPU_RESERVED;
  41
  42       _FPU_SETCW (cw);
  43     }
  44
  45   /* Do nothing if a VFP unit isn't present.  */
  46 }