| 1 | /* Enable floating-point exceptions. |
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| 2 | Copyright (C) 2001-2022 Free Software Foundation, Inc. |
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| 3 | This file is part of the GNU C Library. |
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| 4 | |
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| 5 | The GNU C Library is free software; you can redistribute it and/or |
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| 6 | modify it under the terms of the GNU Lesser General Public |
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| 7 | License as published by the Free Software Foundation; either |
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| 8 | version 2.1 of the License, or (at your option) any later version. |
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| 9 | |
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| 10 | The GNU C Library is distributed in the hope that it will be useful, |
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| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 13 | Lesser General Public License for more details. |
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| 14 | |
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| 15 | You should have received a copy of the GNU Lesser General Public |
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| 16 | License along with the GNU C Library; if not, see |
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| 17 | <https://www.gnu.org/licenses/>. */ |
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| 18 | |
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| 19 | #include <fenv.h> |
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| 20 | |
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| 21 | int |
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| 22 | feenableexcept (int excepts) |
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| 23 | { |
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| 24 | unsigned short int new_exc, old_exc; |
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| 25 | unsigned int new; |
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| 26 | |
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| 27 | excepts &= FE_ALL_EXCEPT; |
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| 28 | |
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| 29 | /* Get the current control word of the x87 FPU. */ |
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| 30 | __asm__ ("fstcw %0" : "=m" (*&new_exc)); |
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| 31 | |
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| 32 | old_exc = (~new_exc) & FE_ALL_EXCEPT; |
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| 33 | |
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| 34 | new_exc &= ~excepts; |
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| 35 | __asm__ ("fldcw %0" : : "m" (*&new_exc)); |
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| 36 | |
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| 37 | /* And now the same for the SSE MXCSR register. */ |
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| 38 | __asm__ ("stmxcsr %0" : "=m" (*&new)); |
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| 39 | |
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| 40 | /* The SSE exception masks are shifted by 7 bits. */ |
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| 41 | new &= ~(excepts << 7); |
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| 42 | __asm__ ("ldmxcsr %0" : : "m" (*&new)); |
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| 43 | |
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| 44 | return old_exc; |
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| 45 | } |
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| 46 | |
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