byteswap.h 1.4 KB

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  1. /* Copyright (C) 2011-2018 Free Software Foundation, Inc.
  2. The GNU C Library is free software; you can redistribute it and/or
  3. modify it under the terms of the GNU Lesser General Public
  4. License as published by the Free Software Foundation; either
  5. version 2.1 of the License, or (at your option) any later version.
  6. The GNU C Library is distributed in the hope that it will be useful,
  7. but WITHOUT ANY WARRANTY; without even the implied warranty of
  8. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  9. Lesser General Public License for more details.
  10. You should have received a copy of the GNU Lesser General Public
  11. License along with the GNU C Library. If not, see
  12. <http://www.gnu.org/licenses/>. */
  13. #if !defined _BYTESWAP_H && !defined _NETINET_IN_H && !defined _ENDIAN_H
  14. # error "Never use <bits/byteswap.h> directly; include <byteswap.h> instead."
  15. #endif
  16. #ifndef _BITS_BYTESWAP_H
  17. #define _BITS_BYTESWAP_H 1
  18. #include <bits/types.h>
  19. /* gcc __builtin_bswap64() can constant-fold, etc, so always use it. */
  20. #define __bswap_16(x) ((unsigned short)(__builtin_bswap32(x) >> 16))
  21. #define __bswap_32(x) ((unsigned int)__builtin_bswap32(x))
  22. #define __bswap_64(x) ((__uint64_t)__builtin_bswap64(x))
  23. #define __bswap_constant_16(x) __bswap_16(x)
  24. #define __bswap_constant_32(x) __bswap_32(x)
  25. #define __bswap_constant_64(x) __bswap_64(x)
  26. #endif /* _BITS_BYTESWAP_H */