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e39762f9 | 1 | /* Install given floating-point environment and raise exceptions. |
6d7e8eda | 2 | Copyright (C) 1997-2023 Free Software Foundation, Inc. |
e39762f9 | 3 | This file is part of the GNU C Library. |
e39762f9 DJ |
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 | |
ab84e3ff | 16 | License along with the GNU C Library. If not, see |
5a82c748 | 17 | <https://www.gnu.org/licenses/>. */ |
e39762f9 | 18 | |
18f8524d | 19 | #include <fenv.h> |
a3dd035d | 20 | #include <fpu_control.h> |
a4ca5195 | 21 | #include <arm-features.h> |
e39762f9 | 22 | |
e39762f9 DJ |
23 | |
24 | int | |
8116321f | 25 | __feupdateenv (const fenv_t *envp) |
e39762f9 | 26 | { |
db59bad3 W |
27 | fpu_control_t fpscr, new_fpscr, updated_fpscr; |
28 | int excepts; | |
e39762f9 | 29 | |
1a2f40e5 W |
30 | /* Fail if a VFP unit isn't present. */ |
31 | if (!ARM_HAVE_VFP) | |
32 | return 1; | |
e39762f9 | 33 | |
18f8524d | 34 | _FPU_GETCW (fpscr); |
db59bad3 | 35 | excepts = fpscr & FE_ALL_EXCEPT; |
e39762f9 | 36 | |
db59bad3 W |
37 | if ((envp != FE_DFL_ENV) && (envp != FE_NOMASK_ENV)) |
38 | { | |
39 | /* Merge current exception flags with the saved fenv. */ | |
40 | new_fpscr = envp->__cw | excepts; | |
41 | ||
42 | /* Write new FPSCR if different (ignoring NZCV flags). */ | |
43 | if (((fpscr ^ new_fpscr) & ~_FPU_MASK_NZCV) != 0) | |
44 | _FPU_SETCW (new_fpscr); | |
45 | ||
46 | /* Raise the exceptions if enabled in the new FP state. */ | |
47 | if (excepts & (new_fpscr >> FE_EXCEPT_SHIFT)) | |
0747f818 | 48 | return __feraiseexcept (excepts); |
db59bad3 W |
49 | |
50 | return 0; | |
51 | } | |
52 | ||
53 | /* Preserve the reserved FPSCR flags. */ | |
54 | new_fpscr = fpscr & (_FPU_RESERVED | FE_ALL_EXCEPT); | |
55 | new_fpscr |= (envp == FE_DFL_ENV) ? _FPU_DEFAULT : _FPU_IEEE; | |
56 | ||
57 | if (((new_fpscr ^ fpscr) & ~_FPU_MASK_NZCV) != 0) | |
58 | { | |
59 | _FPU_SETCW (new_fpscr); | |
60 | ||
61 | /* Not all VFP architectures support trapping exceptions, so | |
62 | test whether the relevant bits were set and fail if not. */ | |
63 | _FPU_GETCW (updated_fpscr); | |
64 | ||
65 | if (new_fpscr & ~updated_fpscr) | |
66 | return 1; | |
67 | } | |
68 | ||
69 | /* Raise the exceptions if enabled in the new FP state. */ | |
70 | if (excepts & (new_fpscr >> FE_EXCEPT_SHIFT)) | |
0747f818 | 71 | return __feraiseexcept (excepts); |
e39762f9 | 72 | |
1a2f40e5 | 73 | return 0; |
e39762f9 | 74 | } |
8116321f JM |
75 | libm_hidden_def (__feupdateenv) |
76 | weak_alias (__feupdateenv, feupdateenv) | |
77 | libm_hidden_weak (feupdateenv) |