1 | /* Install given floating-point environment. |
2 | Copyright (C) 2004-2022 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 <fpu_control.h> |
21 | #include <arm-features.h> |
22 | |
23 | |
24 | int |
25 | __fesetenv (const fenv_t *envp) |
26 | { |
27 | fpu_control_t fpscr, new_fpscr, updated_fpscr; |
28 | |
29 | /* Fail if a VFP unit isn't present. */ |
30 | if (!ARM_HAVE_VFP) |
31 | return 1; |
32 | |
33 | _FPU_GETCW (fpscr); |
34 | |
35 | if ((envp != FE_DFL_ENV) && (envp != FE_NOMASK_ENV)) |
36 | { |
37 | /* The new FPSCR is valid, so don't merge the reserved flags. */ |
38 | new_fpscr = envp->__cw; |
39 | |
40 | /* Write new FPSCR if different (ignoring NZCV flags). */ |
41 | if (((fpscr ^ new_fpscr) & ~_FPU_MASK_NZCV) != 0) |
42 | _FPU_SETCW (new_fpscr); |
43 | |
44 | return 0; |
45 | } |
46 | |
47 | /* Preserve the reserved FPSCR flags. */ |
48 | new_fpscr = fpscr & _FPU_RESERVED; |
49 | new_fpscr |= (envp == FE_DFL_ENV) ? _FPU_DEFAULT : _FPU_IEEE; |
50 | |
51 | if (((new_fpscr ^ fpscr) & ~_FPU_MASK_NZCV) != 0) |
52 | { |
53 | _FPU_SETCW (new_fpscr); |
54 | |
55 | /* Not all VFP architectures support trapping exceptions, so |
56 | test whether the relevant bits were set and fail if not. */ |
57 | _FPU_GETCW (updated_fpscr); |
58 | |
59 | return new_fpscr & ~updated_fpscr; |
60 | } |
61 | |
62 | return 0; |
63 | } |
64 | libm_hidden_def (__fesetenv) |
65 | weak_alias (__fesetenv, fesetenv) |
66 | libm_hidden_weak (fesetenv) |
67 | |