1/* Store current floating-point environment.
2 Copyright (C) 2001-2022 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
21int
22__fegetenv (fenv_t *envp)
23{
24 __asm__ ("fnstenv %0\n"
25 /* fnstenv changes the exception mask, so load back the
26 stored environment. */
27 "fldenv %0\n"
28 "stmxcsr %1" : "=m" (*envp), "=m" (envp->__mxcsr));
29
30 /* Success. */
31 return 0;
32}
33libm_hidden_def (__fegetenv)
34weak_alias (__fegetenv, fegetenv)
35libm_hidden_weak (fegetenv)
36

source code of glibc/sysdeps/x86_64/fpu/fegetenv.c