1/* Set current rounding direction.
2   Copyright (C) 1997, 2003, 2004, 2005 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#include <unistd.h>
23
24int
25fesetround (int round)
26{
27  unsigned short int cw;
28
29  if ((round & ~0xc00) != 0)
30    /* ROUND is no valid rounding mode.  */
31    return 1;
32
33  __asm__ ("fnstcw %0" : "=m" (*&cw));
34  cw &= ~0xc00;
35  cw |= round;
36  __asm__ ("fldcw %0" : : "m" (*&cw));
37
38// TODO: temporarily disabled
39#if 0
40  /* If the CPU supports SSE we set the MXCSR as well.  */
41  if ((GLRO(dl_hwcap) & HWCAP_I386_XMM) != 0)
42    {
43      unsigned int xcw;
44
45      __asm__ ("stmxcsr %0" : "=m" (*&xcw));
46      xcw &= ~0x6000;
47      xcw |= round << 3;
48      __asm__ ("ldmxcsr %0" : : "m" (*&xcw));
49    }
50#endif
51
52  return 0;
53}
54libm_hidden_def (fesetround)
55