1/* Enable floating-point exceptions.
2 Copyright (C) 2001-2021 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Andreas Jaeger <aj@suse.de>, 2001.
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, see
18 <https://www.gnu.org/licenses/>. */
19
20#include <fenv.h>
21
22int
23feenableexcept (int excepts)
24{
25 unsigned short int new_exc, old_exc;
26 unsigned int new;
27
28 excepts &= FE_ALL_EXCEPT;
29
30 /* Get the current control word of the x87 FPU. */
31 __asm__ ("fstcw %0" : "=m" (*&new_exc));
32
33 old_exc = (~new_exc) & FE_ALL_EXCEPT;
34
35 new_exc &= ~excepts;
36 __asm__ ("fldcw %0" : : "m" (*&new_exc));
37
38 /* And now the same for the SSE MXCSR register. */
39 __asm__ ("stmxcsr %0" : "=m" (*&new));
40
41 /* The SSE exception masks are shifted by 7 bits. */
42 new &= ~(excepts << 7);
43 __asm__ ("ldmxcsr %0" : : "m" (*&new));
44
45 return old_exc;
46}
47