fenv.h 2.4 KB

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  1. /* Copyright (C) 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, write to the Free
  13. Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  14. 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
  19. of the appropriate bits in the FPU control word. */
  20. enum
  21. {
  22. FE_INEXACT = 0x04,
  23. #define FE_INEXACT FE_INEXACT
  24. FE_UNDERFLOW = 0x08,
  25. #define FE_UNDERFLOW FE_UNDERFLOW
  26. FE_OVERFLOW = 0x10,
  27. #define FE_OVERFLOW FE_OVERFLOW
  28. FE_DIVBYZERO = 0x20,
  29. #define FE_DIVBYZERO FE_DIVBYZERO
  30. FE_INVALID = 0x40,
  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 MIPS FPU supports all of the four defined rounding modes. We
  36. use again the bit positions in the FPU control word as the values
  37. for the appropriate macros. */
  38. enum
  39. {
  40. FE_TONEAREST = 0x0,
  41. #define FE_TONEAREST FE_TONEAREST
  42. FE_TOWARDZERO = 0x1,
  43. #define FE_TOWARDZERO FE_TOWARDZERO
  44. FE_UPWARD = 0x2,
  45. #define FE_UPWARD FE_UPWARD
  46. FE_DOWNWARD = 0x3
  47. #define FE_DOWNWARD FE_DOWNWARD
  48. };
  49. /* Type representing exception flags. */
  50. typedef unsigned short int fexcept_t;
  51. /* Type representing floating-point environment. This function corresponds
  52. to the layout of the block written by the `fstenv'. */
  53. typedef struct
  54. {
  55. unsigned int __fp_control_register;
  56. }
  57. fenv_t;
  58. /* If the default argument is used we use this value. */
  59. #define FE_DFL_ENV ((__const fenv_t *) -1)
  60. #ifdef __USE_GNU
  61. /* Floating-point environment where none of the exception is masked. */
  62. # define FE_NOMASK_ENV ((__const fenv_t *) -2)
  63. #endif