1  /* Store current floating-point environment.
       2     Copyright (C) 1997-2023 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  
      24  int
      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)
      42  strong_alias (__fegetenv, __old_fegetenv)
      43  compat_symbol (libm, __old_fegetenv, fegetenv, GLIBC_2_1);
      44  #endif
      45  
      46  libm_hidden_def (__fegetenv)
      47  libm_hidden_ver (__fegetenv, fegetenv)
      48  versioned_symbol (libm, __fegetenv, fegetenv, GLIBC_2_2);