feholdexcpt.c 1.4 KB

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  1. /* Store current floating-point environment and clear exceptions.
  2. Copyright (C) 2004, 2006 Free Software Foundation, Inc.
  3. This file is part of the GNU C Library.
  4. Contributed by Aldy Hernandez <aldyh@redhat.com>, 2004.
  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. 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.
  13. You should have received a copy of the GNU Lesser General Public
  14. License along with the GNU C Library; if not, write to the Free
  15. Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  16. 02111-1307 USA. */
  17. #include "fenv_libc.h"
  18. #include <syscall.h>
  19. #include <sys/prctl.h>
  20. int
  21. feholdexcept (fenv_t *envp)
  22. {
  23. fenv_union_t u;
  24. INTERNAL_SYSCALL_DECL (err);
  25. /* Get the current state. */
  26. INTERNAL_SYSCALL (prctl, err, 2, PR_GET_FPEXC, &u.l[0]);
  27. u.l[1] = fegetenv_register ();
  28. *envp = u.fenv;
  29. /* Clear everything except for the rounding mode. */
  30. u.l[1] &= 3;
  31. /* Put the new state in effect. */
  32. fesetenv_register (u.l[1]);
  33. return 0;
  34. }
  35. libm_hidden_def (feholdexcept)