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author | Janne Grunau <janne-libav@jannau.net> | 2014-02-13 12:27:17 +0100 |
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committer | Janne Grunau <janne-libav@jannau.net> | 2014-02-14 18:34:04 +0100 |
commit | 98fdfa99704f1cfef3d3a26c580b92749b6b64cb (patch) | |
tree | 57d3ad6e86479a6d9b32d0fa8fd91f424f73f859 /libpostproc | |
parent | 3fbad00714698f59c6326edfcc63db87f525e7c0 (diff) | |
download | ffmpeg-98fdfa99704f1cfef3d3a26c580b92749b6b64cb.tar.gz |
ppc: reduce overreads when loading 8 pixels in altivec dsp functions
Altivec can only load naturally aligned vectors. To handle possibly
unaligned data a second vector is loaded from an offset of the original
location and the data is recovered through a vector permutation.
Overreads are minimal if the offset for second load points to the last
element of data. This is 7 for loading eight 8-bit pixels and overreads
are reduced from 16 bytes to 8 bytes if the pixels are 64-bit aligned.
For unaligned pixels the overread is reduced from 23 bytes to 15 bytes
in the worst case.
Diffstat (limited to 'libpostproc')
0 files changed, 0 insertions, 0 deletions