sysdeps/x86_64/fpu/fegetround.c

   1 /* Return current rounding direction.
   2    Copyright (C) 1997, 2001 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #include <fenv.h>
  22
  23 int
  24 fegetround (void)
  25 {
  26   int cw;
  27   /* We only check the x87 FPU unit.  The SSE unit should be the same
  28      - and if it's not the same there's no way to signal it.  */
  29
  30   __asm__ ("fnstcw %0" : "=m" (*&cw));
  31
  32   return cw & 0xc00;
  33 }