diff options
| author | Martin Storsjö <martin@martin.st> | 2016-08-01 10:04:42 +0300 |
|---|---|---|
| committer | Martin Storsjö <martin@martin.st> | 2016-08-02 11:33:23 +0300 |
| commit | f79d847400d218cfd0b95f10358fe6e65ec3c9c4 (patch) | |
| tree | 358ae373ff66e2f61e68bdcfb8491d7bc63bc6f2 /libavutil/intreadwrite.h | |
| parent | 230b1c070baa3b6d4bd590426a365b843d60ff50 (diff) | |
intreadwrite: Use the __unaligned keyword on MSVC for ARM and x86_64
AV_WN64 is meant for unaligned data, but the existing av_alias* unions
(without a definition for the av_alias attribute - we don't have one
for MSVC) indicate to the compiler that they would have sufficient
alignment for normal access, i.e. the compiler is free to assume
8 byte alignment.
On ARM, this makes sure that AV_WN64 (or two consecutive AV_WN32) is
done with two str instructions instead of one strd.
Signed-off-by: Martin Storsjö <martin@martin.st>
Diffstat (limited to 'libavutil/intreadwrite.h')
| -rw-r--r-- | libavutil/intreadwrite.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/libavutil/intreadwrite.h b/libavutil/intreadwrite.h index 5f65957ce5..32747b21cb 100644 --- a/libavutil/intreadwrite.h +++ b/libavutil/intreadwrite.h @@ -197,6 +197,11 @@ union unaligned_16 { uint16_t l; } __attribute__((packed)) av_alias; # define AV_RN(s, p) (*((const __unaligned uint##s##_t*)(p))) # define AV_WN(s, p, v) (*((__unaligned uint##s##_t*)(p)) = (v)) +#elif defined(_MSC_VER) && (defined(_M_ARM) || defined(_M_X64)) && AV_HAVE_FAST_UNALIGNED + +# define AV_RN(s, p) (*((const __unaligned uint##s##_t*)(p))) +# define AV_WN(s, p, v) (*((__unaligned uint##s##_t*)(p)) = (v)) + #elif AV_HAVE_FAST_UNALIGNED # define AV_RN(s, p) (((const av_alias##s*)(p))->u##s) |