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| author | Martin Storsjö <martin@martin.st> | 2016-07-28 14:30:25 +0300 |
|---|---|---|
| committer | Martin Storsjö <martin@martin.st> | 2016-07-31 22:50:55 +0300 |
| commit | 014773b66bdff4de24f384066d1a85d2a5bb6774 (patch) | |
| tree | 89917984e48c1c2e84d11f2c3b32a3b30d3935b8 | |
| parent | 25bacd0a0c32ae682e6f411b1ac9020aeaabca72 (diff) | |
| download | ffmpeg-014773b66bdff4de24f384066d1a85d2a5bb6774.tar.gz | |
libavutil: Use an intermediate variable in AV_COPY*U
If AV_RN and AV_WN are macros with multiple individual reads and
writes, the previous version of the AV_COPYU macro would fail if
the reads and writes overlap.
This should not be any less efficient in any case, given a
sensibly optimizing compiler.
Signed-off-by: Martin Storsjö <martin@martin.st>
| -rw-r--r-- | libavutil/intreadwrite.h | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/libavutil/intreadwrite.h b/libavutil/intreadwrite.h index f77fd60f38..cdf1ef47ec 100644 --- a/libavutil/intreadwrite.h +++ b/libavutil/intreadwrite.h @@ -467,7 +467,11 @@ union unaligned_16 { uint16_t l; } __attribute__((packed)) av_alias; * memory locations. */ -#define AV_COPYU(n, d, s) AV_WN##n(d, AV_RN##n(s)); +#define AV_COPYU(n, d, s) \ + do { \ + uint##n##_t val = AV_RN##n(s); \ + AV_WN##n(d, val); \ + } while (0) #ifndef AV_COPY16U # define AV_COPY16U(d, s) AV_COPYU(16, d, s) |