feholdexcpt.c 1.7 KB

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  1. /* Store current floating-point environment and clear exceptions.
  2. Copyright (C) 1997, 1999, 2003, 2004, 2005, 2007
  3. Free Software Foundation, Inc.
  4. This file is part of the GNU C Library.
  5. Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
  6. The GNU C Library is free software; you can redistribute it and/or
  7. modify it under the terms of the GNU Lesser General Public
  8. License as published by the Free Software Foundation; either
  9. version 2.1 of the License, or (at your option) any later version.
  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. You should have received a copy of the GNU Lesser General Public
  15. License along with the GNU C Library; if not, see
  16. <http://www.gnu.org/licenses/>. */
  17. #include <fenv.h>
  18. #include <unistd.h>
  19. int
  20. feholdexcept (fenv_t *envp)
  21. {
  22. fenv_t temp;
  23. /* Store the environment. */
  24. __asm__ ("fnstenv %0" : "=m" (temp));
  25. *envp = temp;
  26. /* Now set all exceptions to non-stop. */
  27. temp.__control_word |= 0x3f;
  28. /* And clear all exceptions. */
  29. temp.__status_word &= ~0x3f;
  30. __asm__ ("fldenv %0" : : "m" (temp));
  31. #if 0
  32. /* If the CPU supports SSE we set the MXCSR as well. */
  33. if ((GLRO(dl_hwcap) & HWCAP_I386_XMM) != 0)
  34. {
  35. unsigned int xwork;
  36. /* Get the current control word. */
  37. __asm__ ("stmxcsr %0" : "=m" (*&xwork));
  38. /* Set all exceptions to non-stop and clear them. */
  39. xwork = (xwork | 0x1f80) & ~0x3f;
  40. __asm__ ("ldmxcsr %0" : : "m" (*&xwork));
  41. }
  42. #endif
  43. return 0;
  44. }