intreadwrite: add AV_RL64A, AV_WL64A

macros for reading and writing 64-bit aligned little-endian values.

these macros are used by the DST decoder and give a performance boost
on platforms that where the compiler must guard against unaligned
memory access.
This commit is contained in:
Peter Ross 2019-01-07 22:12:13 +11:00
parent c563513fdf
commit b4e6d1f597

View File

@ -542,6 +542,21 @@ union unaligned_16 { uint16_t l; } __attribute__((packed)) av_alias;
# define AV_WN64A(p, v) AV_WNA(64, p, v)
#endif
#if AV_HAVE_BIGENDIAN
# define AV_RLA(s, p) av_bswap##s(AV_RN##s##A(p))
# define AV_WLA(s, p, v) AV_WN##s##A(p, av_bswap##s(v))
#else
# define AV_RLA(s, p) AV_RN##s##A(p)
# define AV_WLA(s, p, v) AV_WN##s##A(p, v)
#endif
#ifndef AV_RL64A
# define AV_RL64A(p) AV_RLA(64, p)
#endif
#ifndef AV_WL64A
# define AV_WL64A(p, v) AV_WLA(64, p, v)
#endif
/*
* The AV_COPYxxU macros are suitable for copying data to/from unaligned
* memory locations.