feenablxcpt.c 1.9 KB

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  1. /* Enable floating-point exceptions.
  2. Copyright (C) 2004 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. feenableexcept (int excepts)
  22. {
  23. unsigned int result = 0, pflags, r;
  24. INTERNAL_SYSCALL_DECL (err);
  25. INTERNAL_SYSCALL (prctl, err, 2, PR_GET_FPEXC, &pflags);
  26. /* Save old enable bits. */
  27. if (pflags & PR_FP_EXC_OVF)
  28. result |= FE_OVERFLOW;
  29. if (pflags & PR_FP_EXC_UND)
  30. result |= FE_UNDERFLOW;
  31. if (pflags & PR_FP_EXC_INV)
  32. result |= FE_INVALID;
  33. if (pflags & PR_FP_EXC_DIV)
  34. result |= FE_DIVBYZERO;
  35. if (pflags & PR_FP_EXC_RES)
  36. result |= FE_INEXACT;
  37. if (excepts & FE_INEXACT)
  38. pflags |= PR_FP_EXC_RES;
  39. if (excepts & FE_DIVBYZERO)
  40. pflags |= PR_FP_EXC_DIV;
  41. if (excepts & FE_UNDERFLOW)
  42. pflags |= PR_FP_EXC_UND;
  43. if (excepts & FE_OVERFLOW)
  44. pflags |= PR_FP_EXC_OVF;
  45. if (excepts & FE_INVALID)
  46. pflags |= PR_FP_EXC_INV;
  47. r = INTERNAL_SYSCALL (prctl, err, 2, PR_SET_FPEXC, pflags);
  48. if (INTERNAL_SYSCALL_ERROR_P (r, err))
  49. return -1;
  50. return result;
  51. }