1 /* Install given floating-point environment. 2 Copyright (C) 2004-2021 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 __fesetenv(const fenv_t * envp)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