1/* Disable floating-point exceptions.
2 Copyright (C) 1999-2022 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
24int
25fedisableexcept (int excepts)
26{
27 unsigned short int new_exc, old_exc;
28
29 /* Get the current control word. */
30 __asm__ ("fstcw %0" : "=m" (*&new_exc));
31
32 old_exc = (~new_exc) & FE_ALL_EXCEPT;
33
34 excepts &= FE_ALL_EXCEPT;
35
36 new_exc |= excepts;
37 __asm__ ("fldcw %0" : : "m" (*&new_exc));
38
39 /* If the CPU supports SSE we set the MXCSR as well. */
40 if (CPU_FEATURE_USABLE (SSE))
41 {
42 unsigned int xnew_exc;
43
44 /* Get the current control word. */
45 __asm__ ("stmxcsr %0" : "=m" (*&xnew_exc));
46
47 xnew_exc |= excepts << 7;
48
49 __asm__ ("ldmxcsr %0" : : "m" (*&xnew_exc));
50 }
51
52 return old_exc;
53}
54

source code of glibc/sysdeps/i386/fpu/fedisblxcpt.c