1 /* Clear given exceptions in current floating-point environment.
2 Copyright (C) 1997-2022 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 <https://www.gnu.org/licenses/>. */
18
19 #include <fenv.h>
20 #include <unistd.h>
21 #include <ldsodefs.h>
22 #include <dl-procinfo.h>
23
24 int
__feclearexcept(int excepts)25 __feclearexcept (int excepts)
26 {
27 fenv_t temp;
28
29 /* Mask out unsupported bits/exceptions. */
30 excepts &= FE_ALL_EXCEPT;
31
32 /* Bah, we have to clear selected exceptions. Since there is no
33 `fldsw' instruction we have to do it the hard way. */
34 __asm__ ("fnstenv %0" : "=m" (*&temp));
35
36 /* Clear the relevant bits. */
37 temp.__status_word &= excepts ^ FE_ALL_EXCEPT;
38
39 /* Put the new data in effect. */
40 __asm__ ("fldenv %0" : : "m" (*&temp));
41
42 /* If the CPU supports SSE, we clear the MXCSR as well. */
43 if (CPU_FEATURE_USABLE (SSE))
44 {
45 unsigned int xnew_exc;
46
47 /* Get the current MXCSR. */
48 __asm__ ("stmxcsr %0" : "=m" (*&xnew_exc));
49
50 /* Clear the relevant bits. */
51 xnew_exc &= ~excepts;
52
53 /* Put the new data in effect. */
54 __asm__ ("ldmxcsr %0" : : "m" (*&xnew_exc));
55 }
56
57 /* Success. */
58 return 0;
59 }
60
61 #include <shlib-compat.h>
62 #if SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_2)
63 strong_alias (__feclearexcept, __old_feclearexcept)
64 compat_symbol (libm, __old_feclearexcept, feclearexcept, GLIBC_2_1);
65 #endif
66
67 libm_hidden_ver (__feclearexcept, feclearexcept)
68 versioned_symbol (libm, __feclearexcept, feclearexcept, GLIBC_2_2);
69