sysdeps/i386/fpu/feupdateenv.c

   1 /* Install given floating-point environment and raise exceptions.
   2    Copyright (C) 1997-2024 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 <dl-procinfo.h>
  22 #include <ldsodefs.h>
  23
  24 int
  25 __feupdateenv (const fenv_t *envp)
  26 {
  27   fexcept_t temp;
  28   unsigned int xtemp = 0;
  29
  30   /* Save current exceptions.  */
  31   __asm__ ("fnstsw %0" : "=m" (*&temp));
  32
  33   /* If the CPU supports SSE we test the MXCSR as well.  */
  34   if (CPU_FEATURE_USABLE (SSE))
  35     __asm__ ("stmxcsr %0" : "=m" (*&xtemp));
  36
  37   temp = (temp | xtemp) & FE_ALL_EXCEPT;
  38
  39   /* Install new environment.  */
  40   __fesetenv (envp);
  41
  42   /* Raise the saved exception.  Incidentally for us the implementation
  43      defined format of the values in objects of type fexcept_t is the
  44      same as the ones specified using the FE_* constants.  */
  45   __feraiseexcept ((int) temp);
  46
  47   /* Success.  */
  48   return 0;
  49 }
  50
  51 #include <shlib-compat.h>
  52 #if SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_2)
  53 strong_alias (__feupdateenv, __old_feupdateenv)
  54 compat_symbol (libm, __old_feupdateenv, feupdateenv, GLIBC_2_1);
  55 #endif
  56
  57 libm_hidden_def (__feupdateenv)
  58 libm_hidden_ver (__feupdateenv, feupdateenv)
  59 versioned_symbol (libm, __feupdateenv, feupdateenv, GLIBC_2_2);