1 /* Install given floating-point control modes. x86_64 version.
2 Copyright (C) 2016-2017 Free Software Foundation, Inc.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <http://www.gnu.org/licenses/>. */
19 #include <fpu_control.h>
21 /* All exceptions, including the x86-specific "denormal operand"
23 #define FE_ALL_EXCEPT_X86 (FE_ALL_EXCEPT | __FE_DENORM)
26 fesetmode (const femode_t
*modep
)
30 __asm__ ("stmxcsr %0" : "=m" (mxcsr
));
31 /* Preserve SSE exception flags but restore other state in
33 mxcsr
&= FE_ALL_EXCEPT_X86
;
34 if (modep
== FE_DFL_MODE
)
37 /* Default MXCSR state has all bits zero except for those
38 masking exceptions. */
39 mxcsr
|= FE_ALL_EXCEPT_X86
<< 7;
43 cw
= modep
->__control_word
;
44 mxcsr
|= modep
->__mxcsr
& ~FE_ALL_EXCEPT_X86
;
47 __asm__ ("ldmxcsr %0" : : "m" (mxcsr
));