bswap.h 1.8 KB

12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667
  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. #ifndef AVUTIL_ARM_BSWAP_H
  19. #define AVUTIL_ARM_BSWAP_H
  20. #include <stdint.h>
  21. #include "config.h"
  22. #include "libavutil/attributes.h"
  23. #ifdef __ARMCC_VERSION
  24. #if HAVE_ARMV6
  25. #define av_bswap32 av_bswap32
  26. static av_always_inline av_const uint32_t av_bswap32(uint32_t x)
  27. {
  28. return __rev(x);
  29. }
  30. #endif /* HAVE_ARMV6 */
  31. #elif HAVE_INLINE_ASM
  32. #if HAVE_ARMV6_INLINE
  33. #define av_bswap16 av_bswap16
  34. static av_always_inline av_const unsigned av_bswap16(unsigned x)
  35. {
  36. __asm__("rev16 %0, %0" : "+r"(x));
  37. return x;
  38. }
  39. #endif
  40. #if AV_GCC_VERSION_AT_MOST(4,4)
  41. #define av_bswap32 av_bswap32
  42. static av_always_inline av_const uint32_t av_bswap32(uint32_t x)
  43. {
  44. #if HAVE_ARMV6_INLINE
  45. __asm__("rev %0, %0" : "+r"(x));
  46. #else
  47. uint32_t t;
  48. __asm__ ("eor %1, %0, %0, ror #16 \n\t"
  49. "bic %1, %1, #0xFF0000 \n\t"
  50. "mov %0, %0, ror #8 \n\t"
  51. "eor %0, %0, %1, lsr #8 \n\t"
  52. : "+r"(x), "=&r"(t));
  53. #endif /* HAVE_ARMV6_INLINE */
  54. return x;
  55. }
  56. #endif /* AV_GCC_VERSION_AT_MOST(4,4) */
  57. #endif /* __ARMCC_VERSION */
  58. #endif /* AVUTIL_ARM_BSWAP_H */