fenv.h 2.5 KB

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  1. /* Copyright (C) 1997, 1998, 1999 Free Software Foundation, Inc.
  2. This file is part of the GNU C Library.
  3. The GNU C Library is free software; you can redistribute it and/or
  4. modify it under the terms of the GNU Library General Public License as
  5. published by the Free Software Foundation; either version 2 of the
  6. License, or (at your option) any later version.
  7. The GNU C Library is distributed in the hope that it will be useful,
  8. but WITHOUT ANY WARRANTY; without even the implied warranty of
  9. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  10. Library General Public License for more details.
  11. You should have received a copy of the GNU Library General Public
  12. License along with the GNU C Library; see the file COPYING.LIB. If not,
  13. write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  14. Boston, MA 02111-1307, USA. */
  15. #ifndef _FENV_H
  16. # error "Never use <bits/fenv.h> directly; include <fenv.h> instead."
  17. #endif
  18. /* Define bits representing the exception. We use the bit positions of
  19. the appropriate bits in the FPSR Accrued Exception Byte. */
  20. enum
  21. {
  22. FE_INEXACT = 1 << 3,
  23. #define FE_INEXACT FE_INEXACT
  24. FE_DIVBYZERO = 1 << 4,
  25. #define FE_DIVBYZERO FE_DIVBYZERO
  26. FE_UNDERFLOW = 1 << 5,
  27. #define FE_UNDERFLOW FE_UNDERFLOW
  28. FE_OVERFLOW = 1 << 6,
  29. #define FE_OVERFLOW FE_OVERFLOW
  30. FE_INVALID = 1 << 7
  31. #define FE_INVALID FE_INVALID
  32. };
  33. #define FE_ALL_EXCEPT \
  34. (FE_INEXACT | FE_DIVBYZERO | FE_UNDERFLOW | FE_OVERFLOW | FE_INVALID)
  35. /* The m68k FPU supports all of the four defined rounding modes. We use
  36. the bit positions in the FPCR Mode Control Byte as the values for the
  37. appropriate macros. */
  38. enum
  39. {
  40. FE_TONEAREST = 0,
  41. #define FE_TONEAREST FE_TONEAREST
  42. FE_TOWARDZERO = 1 << 4,
  43. #define FE_TOWARDZERO FE_TOWARDZERO
  44. FE_DOWNWARD = 2 << 4,
  45. #define FE_DOWNWARD FE_DOWNWARD
  46. FE_UPWARD = 3 << 4
  47. #define FE_UPWARD FE_UPWARD
  48. };
  49. /* Type representing exception flags. */
  50. typedef unsigned int fexcept_t;
  51. /* Type representing floating-point environment. This structure
  52. corresponds to the layout of the block written by `fmovem'. */
  53. typedef struct
  54. {
  55. unsigned int __control_register;
  56. unsigned int __status_register;
  57. unsigned int __instruction_address;
  58. }
  59. fenv_t;
  60. /* If the default argument is used we use this value. */
  61. #define FE_DFL_ENV ((fenv_t *) -1)
  62. #ifdef __USE_GNU
  63. /* Floating-point environment where none of the exceptions are masked. */
  64. # define FE_NOMASK_ENV ((fenv_t *) -2)
  65. #endif