Make sure the altivec/vsx functions are faster than C

[lu-zero]

Some functions are quite slower than C according to checkasm.

• [x] Prepare a list
• for each of them
  • [ ] try to speed it up (e.g. by unrolling/rewriting it) or disable them with a proper comment

[sasshka]

Benchmarked with checkasm --bench

• [x] add4x4_idct_c 223 add4x4_idct_altivec 103
• [x] add8x8_idct_c: 935 add8x8_idct_altivec: 434
• [x] add8x8_idct8_c: 1405 add8x8_idct8_altivec: 163
• [x] add8x8_idct_dc_c: 317 add8x8_idct_dc_altivec: 57
• [x] add16x16_idct_c: 3796 add16x16_idct_altivec: 1848
• [x] add16x16_idct8_c: 5631 add16x16_idct8_altivec: 852
• [x] deblock_luma[0]_c: 526 deblock_luma[0]_altivec: 269
• [x] deblock_luma[1]_c: 515 deblock_luma[1]_altivec: 130
• [x] dequant_4x4_cqm_c: 87 dequant_4x4_cqm_altivec: 54
• [x] dequant_4x4_flat_c: 88 dequant_4x4_flat_altivec: 55
• [x] dequant_8x8_cqm_c: 386 dequant_8x8_cqm_altivec: 144
• [x] dequant_8x8_flat_c: 387 dequant_8x8_flat_altivec: 147
• [x] get_ref_4x4_c: 161 get_ref_4x4_altivec: 91
• [x] get_ref_4x8_c: 366 get_ref_4x8_altivec: 152
• [x] get_ref_8x4_c: 252 get_ref_8x4_altivec: 81
• [x] get_ref_8x8_c: 411 get_ref_8x8_altivec: 107
• [x] get_ref_8x16_c: 754 get_ref_8x16_altivec: 172
• [x] get_ref_12x10_c: 690 get_ref_12x10_altivec: 103
• [x] get_ref_16x8_c: 859 get_ref_16x8_altivec: 94
• [x] get_ref_16x16_c: 1669 get_ref_16x16_altivec: 144
• [x] get_ref_20x18_c: 1801 get_ref_20x18_altivec: 397
• [x] hadamard_ac_8x8_c: 1092 hadamard_ac_8x8_altivec: 184
• [x] hadamard_ac_8x16_c: 2168 hadamard_ac_8x16_altivec: 365
• [x] hadamard_ac_16x8_c: 2177 hadamard_ac_16x8_altivec: 370
• [x] hadamard_ac_16x16_c: 4311 hadamard_ac_16x16_altivec: 723
• [x] hpel_filter_c: 32677 hpel_filter_altivec: 4129
• [x] intra_predict_8x8c_p_c: 370 intra_predict_8x8c_p_altivec: 123
• [x] intra_predict_16x16_dc_c: 157 intra_predict_16x16_dc_altivec: 95
• [x] intra_predict_16x16_dc8_c: 87 intra_predict_16x16_dc8_altivec: 21
• [x] intra_predict_16x16_dcl_c: 106 intra_predict_16x16_dcl_altivec: 60
• [x] intra_predict_16x16_dct_c: 101 intra_predict_16x16_dct_altivec: 58
• [x] intra_predict_16x16_h_c: 93 intra_predict_16x16_h_altivec: 39
• [x] intra_predict_16x16_p_c: 1467 intra_predict_16x16_p_altivec: 219
• [x] intra_predict_16x16_v_c: 87 intra_predict_16x16_v_altivec: 43
• [x] intra_sa8d_x3_8x8_c: 3227 intra_sa8d_x3_8x8_altivec: 689
• [x] intra_sad_x3_8x8_c: 960 intra_sad_x3_8x8_altivec: 629
• [x] intra_sad_x3_8x8c_c: 885 intra_sad_x3_8x8c_altivec: 610
• [x] intra_sad_x3_16x16_c: 3667 intra_sad_x3_16x16_altivec: 910
• [ ] intra_satd_x3_4x4_c: 487 intra_satd_x3_4x4_altivec: 564 - slower than C!
• [x] intra_satd_x3_8x8c_c: 2098 intra_satd_x3_8x8c_altivec: 776
• [x] intra_satd_x3_16x16_c: 8179 intra_satd_x3_16x16_altivec: 1864
• [x] load_deinterleave_chroma_fenc_c: 281 load_deinterleave_chroma_fenc_altivec: 48
• [x] lowres_init_c: 35776 lowres_init_altivec: 1226
• [x] mc_chroma_2x2_c: 138 mc_chroma_2x2_altivec: 124
• [x] mc_chroma_2x4_c: 256 mc_chroma_2x4_altivec: 218
• [x] mc_chroma_4x2_c: 269 mc_chroma_4x2_altivec: 124
• [x] mc_chroma_4x4_c: 432 mc_chroma_4x4_altivec: 148
• [x] mc_chroma_4x8_c: 813 mc_chroma_4x8_altivec: 220
• [x] mc_luma_8x4_c: 252 mc_luma_8x4_altivec: 84
• [x] mc_luma_8x8_c: 411 mc_luma_8x8_altivec: 127
• [x] mc_luma_8x16_c: 754 mc_luma_8x16_altivec: 184
• [x] mc_luma_16x8_c: 860 mc_luma_16x8_altivec: 102
• [x] mc_luma_16x16_c: 1670 mc_luma_16x16_altivec: 158
• [x] plane_copy_deinterleave_c: 3897 plane_copy_deinterleave_altivec: 513
• [x] plane_copy_deinterleave_rgb_c: 2046 plane_copy_deinterleave_rgb_altivec: 453
• [x] plane_copy_interleave_c: 3816 plane_copy_interleave_altivec: 1306
• [x] plane_copy_swap_c: 3930 plane_copy_swap_altivec: 821
• [ ] quant_2x2_dc_c: 48 quant_2x2_dc_altivec: 53 - slower than C!
• [x] quant_4x4_c: 135 quant_4x4_altivec: 55
• [x] quant_4x4_dc_c: 123 quant_4x4_dc_altivec: 61
• [x] quant_8x8_c: 660 quant_8x8_altivec: 138
• [x] sa8d_8x8_c: 1037 sa8d_8x8_altivec: 158
• [x] sa8d_16x16_c: 4108 sa8d_16x16_altivec: 631
• [x] sad_8x8_c: 258 sad_8x8_altivec: 110
• [x] sad_8x16_c: 562 sad_8x16_altivec: 215
• [x] sad_16x8_c: 544 sad_16x8_altivec: 111
• [x] sad_16x16_c: 1062 sad_16x16_altivec: 215
• [x] sad_x3_8x8_c: 764 sad_x3_8x8_altivec: 189
• [x] sad_x3_8x16_c: 1740 sad_x3_8x16_altivec: 367
• [x] sad_x3_16x8_c: 1657 sad_x3_16x8_altivec: 193
• [x] sad_x3_16x16_c: 3244 sad_x3_16x16_altivec: 354
• [x] sad_x4_8x8_c: 1016 sad_x4_8x8_altivec: 210
• [x] sad_x4_8x16_c: 2332 sad_x4_8x16_altivec: 453
• [x] sad_x4_16x8_c: 2223 sad_x4_16x8_altivec: 223
• [x] sad_x4_16x16_c: 4354 sad_x4_16x16_altivec: 407
• [x] satd_4x4_c: 122 satd_4x4_altivec: 112
• [x] satd_4x8_c: 262 satd_4x8_altivec: 174
• [x] satd_8x4_c: 324 satd_8x4_altivec: 148
• [x] satd_8x8_c: 667 satd_8x8_altivec: 187
• [x] satd_8x16_c: 1323 satd_8x16_altivec: 322
• [x] satd_16x8_c: 1319 satd_16x8_altivec: 305
• [x] satd_16x16_c: 2620 satd_16x16_altivec: 529
• [x] ssd_8x8_c: 244 ssd_8x8_altivec: 110
• [x] ssd_16x16_c: 972 ssd_16x16_altivec: 163
• [x] ssim_core_c: 508 ssim_core_altivec: 84
• [x] store_interleave_chroma_c: 290 store_interleave_chroma_altivec: 81
• [x] sub4x4_dct_c: 141 sub4x4_dct_altivec: 45
• [x] sub8x8_dct_c: 574 sub8x8_dct_altivec: 94
• [x] sub8x8_dct8_c: 1350 sub8x8_dct8_altivec: 117
• [x] sub8x8_dct_dc_c: 188 sub8x8_dct_dc_altivec: 104
• [x] sub16x16_dct_c: 2281 sub16x16_dct_altivec: 410
• [x] sub16x16_dct8_c: 5411 sub16x16_dct8_altivec: 506
• [x] var_8x8_c: 221 var_8x8_altivec: 57
• [x] var_16x16_c: 776 var_16x16_altivec: 181
• [x] weight_w4_c: 544 weight_w4_altivec: 354
• [x] weight_w8_c: 991 weight_w8_altivec: 381
• [x] weight_w16_c: 1927 weight_w16_altivec: 389
• [x] weight_w20_c: 5679 weight_w20_altivec: 622
• [x] zigzag_interleave_8x8_cavlc_frame_c: 176 zigzag_interleave_8x8_cavlc_frame_altivec: 45
• [x] zigzag_scan_4x4_field_c: 11 zigzag_scan_4x4_field_altivec: 9
• [x] zigzag_scan_4x4_frame_c: 25 zigzag_scan_4x4_frame_altivec: 8
• [x] zigzag_scan_8x8_frame_c: 94 zigzag_scan_8x8_frame_altivec: 68

[malvanos]

@sasshka What machine are you using?

In Power9 with gcc 7.3.0 Ubuntu 18.04 running on VM, I have slower performance on these functions:

quant_2x2_dc_c: 77 quant_2x2_dc_altivec: 85 satd_4x4_c: 128 satd_4x4_altivec: 136 intra_satd_x3_4x4_c: 439 intra_satd_x3_4x4_altivec: 439 zigzag_scan_8x8_frame_c: 125 zigzag_scan_8x8_frame_altivec: 129