1 | /* Install given floating-point control modes. i386 version. |
2 | Copyright (C) 2016-2022 Free Software Foundation, Inc. |
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 |
17 | <https://www.gnu.org/licenses/>. */ |
18 | |
19 | #include <fenv.h> |
20 | #include <fpu_control.h> |
21 | #include <unistd.h> |
22 | #include <ldsodefs.h> |
23 | #include <dl-procinfo.h> |
24 | |
25 | /* All exceptions, including the x86-specific "denormal operand" |
26 | exception. */ |
27 | #define FE_ALL_EXCEPT_X86 (FE_ALL_EXCEPT | __FE_DENORM) |
28 | |
29 | int |
30 | fesetmode (const femode_t *modep) |
31 | { |
32 | fpu_control_t cw; |
33 | if (modep == FE_DFL_MODE) |
34 | cw = _FPU_DEFAULT; |
35 | else |
36 | cw = modep->__control_word; |
37 | _FPU_SETCW (cw); |
38 | if (CPU_FEATURE_USABLE (SSE)) |
39 | { |
40 | unsigned int mxcsr; |
41 | __asm__ ("stmxcsr %0" : "=m" (mxcsr)); |
42 | /* Preserve SSE exception flags but restore other state in |
43 | MXCSR. */ |
44 | mxcsr &= FE_ALL_EXCEPT_X86; |
45 | if (modep == FE_DFL_MODE) |
46 | /* Default MXCSR state has all bits zero except for those |
47 | masking exceptions. */ |
48 | mxcsr |= FE_ALL_EXCEPT_X86 << 7; |
49 | else |
50 | mxcsr |= modep->__mxcsr & ~FE_ALL_EXCEPT_X86; |
51 | __asm__ ("ldmxcsr %0" : : "m" (mxcsr)); |
52 | } |
53 | return 0; |
54 | } |
55 | |