[FFmpeg-devel] libavcodec/exr : add X86 64 SIMD for reorder pixels (SSE and AVX2) (v4)

Martin Vignali martin.vignali at gmail.com
Sun Sep 17 21:22:49 EEST 2017


Following Henrik Grammer comments
new patch in attach

replace int size by ptrdiff_t size

I simplify the code, keeping only 1 loop (more easy to read, and doesn't
have a real impact on speed)
i use the SBUTTERFLY Macro for sse
for avx2 i keep my previous approach

Pass fate-exr tests for me (os X)

Current benchmark
239920 decicycles in reorder_pixels_zip,  130958 runs,    114 skips
bench: utime=101.367s

283768 decicycles in reorder_pixels_zip,  130948 runs,    124 skips
bench: utime=101.424s

3119101 decicycles in reorder_pixels_zip,  130429 runs,    643 skips
bench: utime=114.414s

The result of the suggested asm by Henrik
AVX2 :
258602 decicycles in reorder_pixels_zip,  130853 runs,    219 skips

285167 decicycles in reorder_pixels_zip,  130863 runs,    209 skips

In term of speed using -benchmark, the difference with the current patch is
hard to see.

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