stdlib-bsearch.h 1.3 KB

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  1. /* Perform binary search - inline version.
  2. Copyright (C) 1991-2016 Free Software Foundation, Inc.
  3. This file is part of the GNU C Library.
  4. The GNU C Library is free software; you can redistribute it and/or
  5. modify it under the terms of the GNU Lesser General Public
  6. License as published by the Free Software Foundation; either
  7. version 2.1 of the License, or (at your option) any later version.
  8. The GNU C Library is distributed in the hope that it will be useful,
  9. but WITHOUT ANY WARRANTY; without even the implied warranty of
  10. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  11. Lesser General Public License for more details.
  12. You should have received a copy of the GNU Lesser General Public
  13. License along with the GNU C Library; if not, see
  14. <http://www.gnu.org/licenses/>. */
  15. __extern_inline void *
  16. bsearch (const void *__key, const void *__base, size_t __nmemb, size_t __size,
  17. __compar_fn_t __compar)
  18. {
  19. size_t __l, __u, __idx;
  20. const void *__p;
  21. int __comparison;
  22. __l = 0;
  23. __u = __nmemb;
  24. while (__l < __u)
  25. {
  26. __idx = (__l + __u) / 2;
  27. __p = (void *) (((const char *) __base) + (__idx * __size));
  28. __comparison = (*__compar) (__key, __p);
  29. if (__comparison < 0)
  30. __u = __idx;
  31. else if (__comparison > 0)
  32. __l = __idx + 1;
  33. else
  34. return (void *) __p;
  35. }
  36. return NULL;
  37. }