1/* Store current floating-point environment.
2 Copyright (C) 1997-2022 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 <unistd.h>
21#include <ldsodefs.h>
22#include <dl-procinfo.h>
23
24int
25__fegetenv (fenv_t *envp)
26{
27 __asm__ ("fnstenv %0" : "=m" (*envp));
28 /* And load it right back since the processor changes the mask.
29 Intel thought this opcode to be used in interrupt handlers which
30 would block all exceptions. */
31 __asm__ ("fldenv %0" : : "m" (*envp));
32
33 if (CPU_FEATURE_USABLE (SSE))
34 __asm__ ("stmxcsr %0" : "=m" (envp->__eip));
35
36 /* Success. */
37 return 0;
38}
39
40#include <shlib-compat.h>
41#if SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_2)
42strong_alias (__fegetenv, __old_fegetenv)
43compat_symbol (libm, __old_fegetenv, fegetenv, GLIBC_2_1);
44#endif
45
46libm_hidden_def (__fegetenv)
47libm_hidden_ver (__fegetenv, fegetenv)
48versioned_symbol (libm, __fegetenv, fegetenv, GLIBC_2_2);
49

source code of glibc/sysdeps/i386/fpu/fegetenv.c