mathinline.h 1.6 KB

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  1. /* Inline math functions for x86-64.
  2. Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
  3. This file is part of the GNU C Library.
  4. Contributed by Andreas Jaeger <aj@suse.de>, 2002.
  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, see
  15. <http://www.gnu.org/licenses/>. */
  16. #ifndef _MATH_H
  17. # error "Never use <bits/mathinline.h> directly; include <math.h> instead."
  18. #endif
  19. #ifdef __cplusplus
  20. # define __MATH_INLINE __inline
  21. #else
  22. # define __MATH_INLINE __extern_inline
  23. #endif
  24. #if defined __USE_ISOC99 && defined __GNUC__ && __GNUC__ >= 2
  25. /* Test for negative number. Used in the signbit() macro. */
  26. __MATH_INLINE int
  27. __NTH (__signbitf (float __x))
  28. {
  29. __extension__ union { float __f; int __i; } __u = { __f: __x };
  30. return __u.__i < 0;
  31. }
  32. __MATH_INLINE int
  33. __NTH (__signbit (double __x))
  34. {
  35. __extension__ union { double __d; int __i[2]; } __u = { __d: __x };
  36. return __u.__i[1] < 0;
  37. }
  38. __MATH_INLINE int
  39. __NTH (__signbitl (long double __x))
  40. {
  41. __extension__ union { long double __l; int __i[3]; } __u = { __l: __x };
  42. return (__u.__i[2] & 0x8000) != 0;
  43. }
  44. #endif