| xf.li | bfc6e71 | 2025-02-07 01:54:34 -0800 | [diff] [blame^] | 1 | /* Install given floating-point environment and raise exceptions. |
| 2 | Copyright (C) 1997-2016 Free Software Foundation, Inc. |
| 3 | This file is part of the GNU C Library. |
| 4 | Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. |
| 5 | |
| 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. |
| 10 | |
| 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. |
| 15 | |
| 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/>. */ |
| 19 | |
| 20 | #include <fenv_libc.h> |
| 21 | #include <fpu_control.h> |
| 22 | |
| 23 | #define _FPU_MASK_ALL (_FPU_MASK_ZM | _FPU_MASK_OM | _FPU_MASK_UM | _FPU_MASK_XM | _FPU_MASK_IM) |
| 24 | |
| 25 | int |
| 26 | __feupdateenv (const fenv_t *envp) |
| 27 | { |
| 28 | fenv_union_t old, new; |
| 29 | |
| 30 | /* Save the currently set exceptions. */ |
| 31 | new.fenv = *envp; |
| 32 | old.fenv = fegetenv_register (); |
| 33 | |
| 34 | /* Restore rounding mode and exception enable from *envp and merge |
| 35 | exceptions. Leave fraction rounded/inexact and FP result/CC bits |
| 36 | unchanged. */ |
| 37 | new.l = (old.l & 0xffffffff1fffff00LL) | (new.l & 0x1ff80fff); |
| 38 | |
| 39 | /* If the old env has no enabled exceptions and the new env has any enabled |
| 40 | exceptions, then unmask SIGFPE in the MSR FE0/FE1 bits. This will put |
| 41 | the hardware into "precise mode" and may cause the FPU to run slower on |
| 42 | some hardware. */ |
| 43 | if ((old.l & _FPU_MASK_ALL) == 0 && (new.l & _FPU_MASK_ALL) != 0) |
| 44 | (void) __fe_nomask_env_priv (); |
| 45 | |
| 46 | /* If the old env had any enabled exceptions and the new env has no enabled |
| 47 | exceptions, then mask SIGFPE in the MSR FE0/FE1 bits. This may allow the |
| 48 | FPU to run faster because it always takes the default action and can not |
| 49 | generate SIGFPE. */ |
| 50 | if ((old.l & _FPU_MASK_ALL) != 0 && (new.l & _FPU_MASK_ALL) == 0) |
| 51 | (void)__fe_mask_env (); |
| 52 | |
| 53 | /* Atomically enable and raise (if appropriate) exceptions set in `new'. */ |
| 54 | fesetenv_register (new.fenv); |
| 55 | |
| 56 | /* Success. */ |
| 57 | return 0; |
| 58 | } |
| 59 | |
| 60 | #include <shlib-compat.h> |
| 61 | #if SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_2) |
| 62 | strong_alias (__feupdateenv, __old_feupdateenv) |
| 63 | compat_symbol (libm, __old_feupdateenv, feupdateenv, GLIBC_2_1); |
| 64 | #endif |
| 65 | |
| 66 | libm_hidden_def (__feupdateenv) |
| 67 | libm_hidden_ver (__feupdateenv, feupdateenv) |
| 68 | versioned_symbol (libm, __feupdateenv, feupdateenv, GLIBC_2_2); |