bswap.h 2.1 KB

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  1. /*
  2. * This file is part of FFmpeg.
  3. *
  4. * FFmpeg 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. *
  9. * FFmpeg 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. *
  14. * You should have received a copy of the GNU Lesser General Public
  15. * License along with FFmpeg; if not, write to the Free Software
  16. * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  17. */
  18. /**
  19. * @file
  20. * byte swapping routines
  21. */
  22. #ifndef AVUTIL_X86_BSWAP_H
  23. #define AVUTIL_X86_BSWAP_H
  24. #include <stdint.h>
  25. #if defined(_MSC_VER)
  26. #include <stdlib.h>
  27. #include <intrin.h>
  28. #endif
  29. #include "config.h"
  30. #include "libavutil/attributes.h"
  31. #if defined(_MSC_VER)
  32. #define av_bswap16 av_bswap16
  33. static av_always_inline av_const uint16_t av_bswap16(uint16_t x)
  34. {
  35. return _rotr16(x, 8);
  36. }
  37. #define av_bswap32 av_bswap32
  38. static av_always_inline av_const uint32_t av_bswap32(uint32_t x)
  39. {
  40. return _byteswap_ulong(x);
  41. }
  42. #if ARCH_X86_64
  43. #define av_bswap64 av_bswap64
  44. static inline uint64_t av_const av_bswap64(uint64_t x)
  45. {
  46. return _byteswap_uint64(x);
  47. }
  48. #endif
  49. #elif HAVE_INLINE_ASM
  50. #if AV_GCC_VERSION_AT_MOST(4,0)
  51. #define av_bswap16 av_bswap16
  52. static av_always_inline av_const unsigned av_bswap16(unsigned x)
  53. {
  54. __asm__("rorw $8, %w0" : "+r"(x));
  55. return x;
  56. }
  57. #endif /* AV_GCC_VERSION_AT_MOST(4,0) */
  58. #if AV_GCC_VERSION_AT_MOST(4,4) || defined(__INTEL_COMPILER)
  59. #define av_bswap32 av_bswap32
  60. static av_always_inline av_const uint32_t av_bswap32(uint32_t x)
  61. {
  62. __asm__("bswap %0" : "+r" (x));
  63. return x;
  64. }
  65. #if ARCH_X86_64
  66. #define av_bswap64 av_bswap64
  67. static inline uint64_t av_const av_bswap64(uint64_t x)
  68. {
  69. __asm__("bswap %0": "=r" (x) : "0" (x));
  70. return x;
  71. }
  72. #endif
  73. #endif /* AV_GCC_VERSION_AT_MOST(4,4) */
  74. #endif /* HAVE_INLINE_ASM */
  75. #endif /* AVUTIL_X86_BSWAP_H */