1 | /* Copyright (C) 2009-2024 Free Software Foundation, Inc. |
---|---|
2 | |
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 License as |
7 | published by the Free Software Foundation; either version 2.1 of the |
8 | 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 | |
22 | int |
23 | __feupdateenv (const fenv_t *envp) |
24 | { |
25 | fpu_control_t fpcr; |
26 | fpu_control_t fpcr_new; |
27 | fpu_control_t updated_fpcr; |
28 | fpu_fpsr_t fpsr; |
29 | fpu_fpsr_t fpsr_new; |
30 | int excepts; |
31 | |
32 | _FPU_GETCW (fpcr); |
33 | _FPU_GETFPSR (fpsr); |
34 | excepts = fpsr & FE_ALL_EXCEPT; |
35 | |
36 | if ((envp != FE_DFL_ENV) && (envp != FE_NOMASK_ENV)) |
37 | { |
38 | fpcr_new = envp->__fpcr; |
39 | fpsr_new = envp->__fpsr | excepts; |
40 | |
41 | if (fpcr != fpcr_new) |
42 | _FPU_SETCW (fpcr_new); |
43 | |
44 | if (fpsr != fpsr_new) |
45 | _FPU_SETFPSR (fpsr_new); |
46 | |
47 | if (excepts & (fpcr_new >> FE_EXCEPT_SHIFT)) |
48 | return __feraiseexcept (excepts: excepts); |
49 | |
50 | return 0; |
51 | } |
52 | |
53 | fpcr_new = fpcr & _FPU_RESERVED; |
54 | fpsr_new = fpsr & (_FPU_FPSR_RESERVED | FE_ALL_EXCEPT); |
55 | |
56 | if (envp == FE_DFL_ENV) |
57 | { |
58 | fpcr_new |= _FPU_DEFAULT; |
59 | fpsr_new |= _FPU_FPSR_DEFAULT; |
60 | } |
61 | else |
62 | { |
63 | fpcr_new |= _FPU_FPCR_IEEE; |
64 | fpsr_new |= _FPU_FPSR_IEEE; |
65 | } |
66 | |
67 | _FPU_SETFPSR (fpsr_new); |
68 | |
69 | if (fpcr != fpcr_new) |
70 | { |
71 | _FPU_SETCW (fpcr_new); |
72 | |
73 | /* Trapping exceptions are optional in AArch64; the relevant enable |
74 | bits in FPCR are RES0 hence the absence of support can be detected |
75 | by reading back the FPCR and comparing with the required value. */ |
76 | _FPU_GETCW (updated_fpcr); |
77 | |
78 | if (fpcr_new & ~updated_fpcr) |
79 | return 1; |
80 | } |
81 | |
82 | if (excepts & (fpcr_new >> FE_EXCEPT_SHIFT)) |
83 | return __feraiseexcept (excepts: excepts); |
84 | |
85 | return 0; |
86 | } |
87 | libm_hidden_def (__feupdateenv) |
88 | weak_alias (__feupdateenv, feupdateenv) |
89 | libm_hidden_weak (feupdateenv) |
90 |