1 /* Install given floating-point environment and raise exceptions.
2    Copyright (C) 2000-2022 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 <string.h>
21 
22 int
__feupdateenv(const fenv_t * envp)23 __feupdateenv (const fenv_t *envp)
24 {
25   union { unsigned long long l; unsigned int sw[2]; } s;
26   fenv_t temp;
27   /* Get the current exception status */
28   __asm__ ("fstd %%fr0,0(%1)	\n\t"
29            "fldd 0(%1),%%fr0	\n\t"
30 	   : "=m" (s.l) : "r" (&s.l));
31 
32   /* Given environment with exception flags not cleared.  */
33   if ((envp != FE_DFL_ENV) && (envp != FE_NOMASK_ENV))
34     {
35       memcpy(&temp, envp, sizeof (fenv_t));
36       temp.__status_word |= s.sw[0] & (FE_ALL_EXCEPT << 27);
37     }
38 
39   /* Default environment with exception flags not cleared.  */
40   if (envp == FE_DFL_ENV)
41     temp.__status_word = s.sw[0] & (FE_ALL_EXCEPT << 27);
42 
43   /* All traps enabled and current exception flags not cleared.  */
44   if (envp == FE_NOMASK_ENV)
45     temp.__status_word = (s.sw[0] & (FE_ALL_EXCEPT << 27)) | FE_ALL_EXCEPT;
46 
47   /* Install new environment.  */
48   __fesetenv (&temp);
49   /* Success.  */
50   return 0;
51 }
52 libm_hidden_def (__feupdateenv)
53 weak_alias (__feupdateenv, feupdateenv)
54 libm_hidden_weak (feupdateenv)
55