1 /* Clear given exceptions in current floating-point environment.
2 Copyright (C) 2001-2017 Free Software Foundation, Inc.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <http://www.gnu.org/licenses/>. */
17
18 #include <fenv.h>
19
20 int
feclearexcept(int excepts)21 feclearexcept (int excepts)
22 {
23 fenv_t temp;
24 unsigned int mxcsr;
25
26 /* Mask out unsupported bits/exceptions. */
27 excepts &= FE_ALL_EXCEPT;
28
29 /* Bah, we have to clear selected exceptions. Since there is no
30 `fldsw' instruction we have to do it the hard way. */
31 __asm__ ("fnstenv %0" : "=m" (*&temp));
32
33 /* Clear the relevant bits. */
34 temp.__status_word &= excepts ^ FE_ALL_EXCEPT;
35
36 /* Put the new data in effect. */
37 __asm__ ("fldenv %0" : : "m" (*&temp));
38
39 /* And the same procedure for SSE. */
40 __asm__ ("stmxcsr %0" : "=m" (*&mxcsr));
41
42 /* Clear the relevant bits. */
43 mxcsr &= ~excepts;
44
45 /* And put them into effect. */
46 __asm__ ("ldmxcsr %0" : : "m" (*&mxcsr));
47
48 /* Success. */
49 return 0;
50 }
51