1 /* Store current floating-point environment and clear exceptions.
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
feholdexcept(fenv_t * envp)21 feholdexcept (fenv_t *envp)
22 {
23 unsigned int mxcsr;
24
25 /* Store the environment. Recall that fnstenv has a side effect of
26 masking all exceptions. Then clear all exceptions. */
27 __asm__ ("fnstenv %0\n\t"
28 "stmxcsr %1\n\t"
29 "fnclex"
30 : "=m" (*envp), "=m" (envp->__mxcsr));
31
32 /* Set the SSE MXCSR register. */
33 mxcsr = (envp->__mxcsr | 0x1f80) & ~0x3f;
34 __asm__ ("ldmxcsr %0" : : "m" (*&mxcsr));
35
36 return 0;
37 }
38