huge_val.h 2.4 KB

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  1. /* `HUGE_VAL' constants for ix86 (where it is infinity).
  2. Used by <stdlib.h> and <math.h> functions for overflow.
  3. Copyright (C) 1992, 1995, 1996, 1997 Free Software Foundation, Inc.
  4. This file is part of the GNU C Library.
  5. The GNU C Library is free software; you can redistribute it and/or
  6. modify it under the terms of the GNU Library General Public License as
  7. published by the Free Software Foundation; either version 2 of the
  8. 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. Library General Public License for more details.
  13. You should have received a copy of the GNU Library General Public
  14. License along with the GNU C Library; see the file COPYING.LIB. If not,
  15. write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16. Boston, MA 02111-1307, USA. */
  17. #ifndef _MATH_H
  18. # error "Never use <bits/huge_val.h> directly; include <math.h> instead."
  19. #endif
  20. #include <features.h>
  21. /* IEEE positive infinity (-HUGE_VAL is negative infinity). */
  22. #define __HUGE_VAL_bytes { 0, 0, 0, 0, 0, 0, 0xf0, 0x7f }
  23. #define __huge_val_t union { unsigned char __c[8]; double __d; }
  24. #ifdef __GNUC__
  25. # define HUGE_VAL (__extension__ \
  26. ((__huge_val_t) { __c: __HUGE_VAL_bytes }).__d)
  27. #else /* Not GCC. */
  28. static __huge_val_t __huge_val = { __HUGE_VAL_bytes };
  29. # define HUGE_VAL (__huge_val.__d)
  30. #endif /* GCC. */
  31. /* ISO C 9X extensions: (float) HUGE_VALF and (long double) HUGE_VALL. */
  32. #ifdef __USE_ISOC9X
  33. # define __HUGE_VALF_bytes { 0, 0, 0x80, 0x7f }
  34. # define __huge_valf_t union { unsigned char __c[4]; float __f; }
  35. # ifdef __GNUC__
  36. # define HUGE_VALF (__extension__ \
  37. ((__huge_valf_t) { __c: __HUGE_VALF_bytes }).__f)
  38. # else /* Not GCC. */
  39. static __huge_valf_t __huge_valf = { __HUGE_VALF_bytes };
  40. # define HUGE_VALF (__huge_valf.__f)
  41. # endif /* GCC. */
  42. # define __HUGE_VALL_bytes { 0, 0, 0, 0, 0, 0, 0, 0x80, 0xff, 0x7f, 0, 0 }
  43. # define __huge_vall_t union { unsigned char __c[12]; long double __ld; }
  44. # ifdef __GNUC__
  45. # define HUGE_VALL (__extension__ \
  46. ((__huge_vall_t) { __c: __HUGE_VALL_bytes }).__ld)
  47. # else /* Not GCC. */
  48. static __huge_vall_t __huge_vall = { __HUGE_VALL_bytes };
  49. # define HUGE_VALL (__huge_vall.__ld)
  50. # endif /* GCC. */
  51. #endif /* __USE_ISOC9X. */