string-fzb.h 1.6 KB

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  1. /* Zero byte detection; boolean. Alpha version.
  2. Copyright (C) 2023-2026 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. #ifndef _STRING_FZB_H
  16. #define _STRING_FZB_H 1
  17. #include <sys/cdefs.h>
  18. #include <string-optype.h>
  19. /* Note that since CMPBGE creates a bit mask rather than a byte mask,
  20. we cannot simply provide a target-specific string-fza.h. */
  21. /* Determine if any byte within X is zero. This is a pure boolean test. */
  22. static __always_inline _Bool
  23. has_zero (op_t x)
  24. {
  25. return __builtin_alpha_cmpbge (0, x) != 0;
  26. }
  27. /* Likewise, but for byte equality between X1 and X2. */
  28. static __always_inline _Bool
  29. has_eq (op_t x1, op_t x2)
  30. {
  31. return has_zero (x1 ^ x2);
  32. }
  33. /* Likewise, but for zeros in X1 and equal bytes between X1 and X2. */
  34. static __always_inline _Bool
  35. has_zero_eq (op_t x1, op_t x2)
  36. {
  37. return has_zero (x1) | has_eq (x1, x2);
  38. }
  39. #endif /* _STRING_FZB_H */