| lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame] | 1 | /* Enable floating-point exceptions. |
| 2 | Copyright (C) 1999, 2000, 2003, 2004 Free Software Foundation, Inc. |
| 3 | This file is part of the GNU C Library. |
| 4 | Contributed by Andreas Jaeger <aj@suse.de>, 1999. |
| 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, write to the Free |
| 18 | Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 19 | 02111-1307 USA. */ |
| 20 | |
| 21 | #include <fenv.h> |
| 22 | #include <unistd.h> |
| 23 | |
| 24 | int |
| 25 | feenableexcept (int excepts) |
| 26 | { |
| 27 | unsigned short int new_exc; |
| 28 | unsigned short int old_exc; |
| 29 | |
| 30 | /* Get the current control word. */ |
| 31 | __asm__ ("fstcw %0" : "=m" (*&new_exc)); |
| 32 | |
| 33 | excepts &= FE_ALL_EXCEPT; |
| 34 | old_exc = (~new_exc) & FE_ALL_EXCEPT; |
| 35 | |
| 36 | new_exc &= ~excepts; |
| 37 | __asm__ ("fldcw %0" : : "m" (*&new_exc)); |
| 38 | |
| 39 | #if 0 |
| 40 | /* If the CPU supports SSE we set the MXCSR as well. */ |
| 41 | if ((GLRO(dl_hwcap) & HWCAP_I386_XMM) != 0) |
| 42 | { |
| 43 | unsigned int xnew_exc; |
| 44 | |
| 45 | /* Get the current control word. */ |
| 46 | __asm__ ("stmxcsr %0" : "=m" (*&xnew_exc)); |
| 47 | |
| 48 | xnew_exc &= ~(excepts << 7); |
| 49 | |
| 50 | __asm__ ("ldmxcsr %0" : : "m" (*&xnew_exc)); |
| 51 | } |
| 52 | #endif |
| 53 | |
| 54 | return old_exc; |
| 55 | } |