fenv.h 2.4 KB

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  1. /* Copyright (C) 1997, 1998, 1999, 2000 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 Lesser General Public
  5. License as published by the Free Software Foundation; either
  6. version 2.1 of the 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. Lesser General Public License for more details.
  11. You should have received a copy of the GNU Lesser General Public
  12. License along with the GNU C Library; if not, see
  13. <http://www.gnu.org/licenses/>. */
  14. #ifndef _FENV_H
  15. # error "Never use <bits/fenv.h> directly; include <fenv.h> instead."
  16. #endif
  17. /* Define bits representing the exception. We use the bit positions of
  18. the appropriate bits in the FPSR Accrued Exception Byte. */
  19. enum
  20. {
  21. FE_INEXACT = 1 << 3,
  22. #define FE_INEXACT FE_INEXACT
  23. FE_DIVBYZERO = 1 << 4,
  24. #define FE_DIVBYZERO FE_DIVBYZERO
  25. FE_UNDERFLOW = 1 << 5,
  26. #define FE_UNDERFLOW FE_UNDERFLOW
  27. FE_OVERFLOW = 1 << 6,
  28. #define FE_OVERFLOW FE_OVERFLOW
  29. FE_INVALID = 1 << 7
  30. #define FE_INVALID FE_INVALID
  31. };
  32. #define FE_ALL_EXCEPT \
  33. (FE_INEXACT | FE_DIVBYZERO | FE_UNDERFLOW | FE_OVERFLOW | FE_INVALID)
  34. /* The m68k FPU supports all of the four defined rounding modes. We use
  35. the bit positions in the FPCR Mode Control Byte as the values for the
  36. appropriate macros. */
  37. enum
  38. {
  39. FE_TONEAREST = 0,
  40. #define FE_TONEAREST FE_TONEAREST
  41. FE_TOWARDZERO = 1 << 4,
  42. #define FE_TOWARDZERO FE_TOWARDZERO
  43. FE_DOWNWARD = 2 << 4,
  44. #define FE_DOWNWARD FE_DOWNWARD
  45. FE_UPWARD = 3 << 4
  46. #define FE_UPWARD FE_UPWARD
  47. };
  48. /* Type representing exception flags. */
  49. typedef unsigned int fexcept_t;
  50. /* Type representing floating-point environment. This structure
  51. corresponds to the layout of the block written by `fmovem'. */
  52. typedef struct
  53. {
  54. unsigned int __control_register;
  55. unsigned int __status_register;
  56. unsigned int __instruction_address;
  57. }
  58. fenv_t;
  59. /* If the default argument is used we use this value. */
  60. #define FE_DFL_ENV ((const fenv_t *) -1)
  61. #ifdef __USE_GNU
  62. /* Floating-point environment where none of the exceptions are masked. */
  63. # define FE_NOMASK_ENV ((const fenv_t *) -2)
  64. #endif