1 /* Install given floating-point environment and raise exceptions.
2 Copyright (C) 1997-2023 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
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.
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.
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/>. */
20 #include <fpu_control.h>
21 #include <arm-features.h>
25 __feupdateenv (const fenv_t
*envp
)
27 fpu_control_t fpscr
, new_fpscr
, updated_fpscr
;
30 /* Fail if a VFP unit isn't present. */
35 excepts
= fpscr
& FE_ALL_EXCEPT
;
37 if ((envp
!= FE_DFL_ENV
) && (envp
!= FE_NOMASK_ENV
))
39 /* Merge current exception flags with the saved fenv. */
40 new_fpscr
= envp
->__cw
| excepts
;
42 /* Write new FPSCR if different (ignoring NZCV flags). */
43 if (((fpscr
^ new_fpscr
) & ~_FPU_MASK_NZCV
) != 0)
44 _FPU_SETCW (new_fpscr
);
46 /* Raise the exceptions if enabled in the new FP state. */
47 if (excepts
& (new_fpscr
>> FE_EXCEPT_SHIFT
))
48 return __feraiseexcept (excepts
);
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
;
57 if (((new_fpscr
^ fpscr
) & ~_FPU_MASK_NZCV
) != 0)
59 _FPU_SETCW (new_fpscr
);
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
);
65 if (new_fpscr
& ~updated_fpscr
)
69 /* Raise the exceptions if enabled in the new FP state. */
70 if (excepts
& (new_fpscr
>> FE_EXCEPT_SHIFT
))
71 return __feraiseexcept (excepts
);
75 libm_hidden_def (__feupdateenv
)
76 weak_alias (__feupdateenv
, feupdateenv
)
77 libm_hidden_weak (feupdateenv
)