x86/vp9lpf: add ff_vp9_loop_filter_[vh]_88_16_{ssse3,avx}.

9680 decicycles in loop_filter_v_88_16_c, 4193765 runs, 539 skips
9233 decicycles in loop_filter_h_88_16_c, 4193751 runs, 553 skips

1929 decicycles in ff_vp9_loop_filter_v_88_16_ssse3, 4194118 runs, 186 skips
2738 decicycles in ff_vp9_loop_filter_h_88_16_ssse3, 4193861 runs, 443 skips

5.978 → 5.417 overall decode time on ped1080p.webm (-threads 1)

Adding SSE2 support should be relatively trivial (just a matter of
changing the pshufb [mask_mix] with something else), patch welcome.

libavcodec/x86/vp9dsp_init.c

@@ -187,6 +187,8 @@ void ff_vp9_loop_filter_h_##size1##_##size2##_##opt(uint8_t *dst, ptrdiff_t stri
 lpf_funcs(16, 16, sse2);
 lpf_funcs(16, 16, ssse3);
 lpf_funcs(16, 16, avx);
+lpf_funcs(88, 16, ssse3);
+lpf_funcs(88, 16, avx);
 
 #undef lpf_funcs
 
@@ -271,6 +273,8 @@ av_cold void ff_vp9dsp_init_x86(VP9DSPContext *dsp)
             dsp->itxfm_add[TX_32X32][ADST_DCT] =
             dsp->itxfm_add[TX_32X32][DCT_ADST] =
             dsp->itxfm_add[TX_32X32][DCT_DCT] = ff_vp9_idct_idct_32x32_add_ssse3;
+            dsp->loop_filter_mix2[1][1][0] = ff_vp9_loop_filter_h_88_16_ssse3;
+            dsp->loop_filter_mix2[1][1][1] = ff_vp9_loop_filter_v_88_16_ssse3;
             dsp->loop_filter_16[0] = ff_vp9_loop_filter_h_16_16_ssse3;
             dsp->loop_filter_16[1] = ff_vp9_loop_filter_v_16_16_ssse3;
         }
@@ -290,6 +294,8 @@ av_cold void ff_vp9dsp_init_x86(VP9DSPContext *dsp)
             dsp->itxfm_add[TX_32X32][ADST_DCT] =
             dsp->itxfm_add[TX_32X32][DCT_ADST] =
             dsp->itxfm_add[TX_32X32][DCT_DCT] = ff_vp9_idct_idct_32x32_add_avx;
+            dsp->loop_filter_mix2[1][1][0] = ff_vp9_loop_filter_h_88_16_avx;
+            dsp->loop_filter_mix2[1][1][1] = ff_vp9_loop_filter_v_88_16_avx;
             dsp->loop_filter_16[0] = ff_vp9_loop_filter_h_16_16_avx;
             dsp->loop_filter_16[1] = ff_vp9_loop_filter_v_16_16_avx;
         }