1 /* Install given floating-point environment and raise exceptions.
2 Copyright (C) 1997-2014 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library. If not, see
18 <http://www.gnu.org/licenses/>. */
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)