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ec94343f | 1 | /* Install given floating-point control modes. x86_64 version. |
2b778ceb | 2 | Copyright (C) 2016-2021 Free Software Foundation, Inc. |
ec94343f JM |
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 | |
5a82c748 | 17 | <https://www.gnu.org/licenses/>. */ |
ec94343f JM |
18 | |
19 | #include <fenv.h> | |
20 | #include <fpu_control.h> | |
21 | ||
22 | /* All exceptions, including the x86-specific "denormal operand" | |
23 | exception. */ | |
24 | #define FE_ALL_EXCEPT_X86 (FE_ALL_EXCEPT | __FE_DENORM) | |
25 | ||
26 | int | |
27 | fesetmode (const femode_t *modep) | |
28 | { | |
29 | fpu_control_t cw; | |
30 | unsigned int mxcsr; | |
31 | __asm__ ("stmxcsr %0" : "=m" (mxcsr)); | |
32 | /* Preserve SSE exception flags but restore other state in | |
33 | MXCSR. */ | |
34 | mxcsr &= FE_ALL_EXCEPT_X86; | |
35 | if (modep == FE_DFL_MODE) | |
36 | { | |
37 | cw = _FPU_DEFAULT; | |
38 | /* Default MXCSR state has all bits zero except for those | |
39 | masking exceptions. */ | |
40 | mxcsr |= FE_ALL_EXCEPT_X86 << 7; | |
41 | } | |
42 | else | |
43 | { | |
44 | cw = modep->__control_word; | |
45 | mxcsr |= modep->__mxcsr & ~FE_ALL_EXCEPT_X86; | |
46 | } | |
47 | _FPU_SETCW (cw); | |
48 | __asm__ ("ldmxcsr %0" : : "m" (mxcsr)); | |
49 | return 0; | |
50 | } |