Keep track of relative pixel offsets and utilize pshufb to efficiently extract relevant pixels for horizontal scaling ratios <= 8. Because pshufb does not cross 128-bit lanes, the overhead of address calculations and loads is relatively greater as compared with an SSSE3/SSE4.1 implementation. Fall back to a generic approach for ratios > 8. The implementation assumes that data beyond the end of each line, before the next line begins, can be dirtied; which AFAICT is safe with the current usage of these routines. Speedup is ~8.52x/~6.89x (32-bit/64-bit) for horizontal ratios <= 2, ~7.81x/~6.13x for ratios within (2, 4], ~5.81x/~4.52x for ratios within (4, 8], and ~5.06x/~4.09x for ratios > 8 when not memory-bound on Haswell as compared with the current SSE2 implementation.
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| @@ -110,6 +110,7 @@ void CDownsampling::InitDownsampleFuncs (SDownsampleFuncs& sDownsampleFunc, int · 109 unmodified lines | ||
| 110 | 110 | sDownsampleFunc.pfGeneralRatioChroma = GeneralBilinearAccurateDownsamplerWrap_sse41; |
| 111 | 111 | } |
| 112 | 112 | if (iCpuFlag & WELS_CPU_AVX2) { |
| 113 | + sDownsampleFunc.pfGeneralRatioChroma = GeneralBilinearAccurateDownsamplerWrap_avx2; | |
| 113 | 114 | sDownsampleFunc.pfGeneralRatioLuma = GeneralBilinearFastDownsamplerWrap_avx2; |
| 114 | 115 | } |
| 115 | 116 | #endif//X86_ASM |