| 1 | /* Copyright (C) 1997-2024 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 | __fesetenv (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 | |
| 31 | _FPU_GETCW (fpcr); |
| 32 | |
| 33 | if ((envp != FE_DFL_ENV) && (envp != FE_NOMASK_ENV)) |
| 34 | { |
| 35 | /* The new FPCR/FPSR are valid, so don't merge the reserved flags. */ |
| 36 | fpcr_new = envp->__fpcr; |
| 37 | |
| 38 | if (fpcr != fpcr_new) |
| 39 | _FPU_SETCW (fpcr_new); |
| 40 | |
| 41 | _FPU_SETFPSR (envp->__fpsr); |
| 42 | return 0; |
| 43 | } |
| 44 | |
| 45 | _FPU_GETFPSR (fpsr); |
| 46 | fpcr_new = fpcr & _FPU_RESERVED; |
| 47 | fpsr_new = fpsr & _FPU_FPSR_RESERVED; |
| 48 | |
| 49 | if (envp == FE_DFL_ENV) |
| 50 | { |
| 51 | fpcr_new |= _FPU_DEFAULT; |
| 52 | fpsr_new |= _FPU_FPSR_DEFAULT; |
| 53 | } |
| 54 | else |
| 55 | { |
| 56 | fpcr_new |= _FPU_FPCR_IEEE; |
| 57 | fpsr_new |= _FPU_FPSR_IEEE; |
| 58 | } |
| 59 | |
| 60 | _FPU_SETFPSR (fpsr_new); |
| 61 | |
| 62 | if (fpcr != fpcr_new) |
| 63 | { |
| 64 | _FPU_SETCW (fpcr_new); |
| 65 | |
| 66 | /* Trapping exceptions are optional in AArch64; the relevant enable |
| 67 | bits in FPCR are RES0 hence the absence of support can be detected |
| 68 | by reading back the FPCR and comparing with the required value. */ |
| 69 | _FPU_GETCW (updated_fpcr); |
| 70 | |
| 71 | return fpcr_new & ~updated_fpcr; |
| 72 | } |
| 73 | |
| 74 | return 0; |
| 75 | } |
| 76 | libm_hidden_def (__fesetenv) |
| 77 | weak_alias (__fesetenv, fesetenv) |
| 78 | libm_hidden_weak (fesetenv) |
| 79 |