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av1_convolve_scale_neon_dotprod.c (17159B)


      1 /*
      2 * Copyright (c) 2024, Alliance for Open Media. All rights reserved.
      3 *
      4 * This source code is subject to the terms of the BSD 2 Clause License and
      5 * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
      6 * was not distributed with this source code in the LICENSE file, you can
      7 * obtain it at www.aomedia.org/license/software. If the Alliance for Open
      8 * Media Patent License 1.0 was not distributed with this source code in the
      9 * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
     10 */
     11 
     12 #include <assert.h>
     13 #include <arm_neon.h>
     14 #include <stddef.h>
     15 #include <stdint.h>
     16 
     17 #include "config/aom_config.h"
     18 #include "config/av1_rtcd.h"
     19 
     20 #include "aom_dsp/aom_dsp_common.h"
     21 #include "aom_dsp/aom_filter.h"
     22 #include "aom_dsp/arm/mem_neon.h"
     23 #include "aom_dsp/arm/transpose_neon.h"
     24 #include "aom_ports/mem.h"
     25 #include "av1/common/arm/convolve_scale_neon.h"
     26 #include "av1/common/convolve.h"
     27 #include "av1/common/enums.h"
     28 #include "av1/common/filter.h"
     29 
     30 // clang-format off
     31 DECLARE_ALIGNED(16, static const uint8_t, kScale2DotProdPermuteTbl[32]) = {
     32  0, 1, 2, 3, 2, 3, 4, 5, 4, 5,  6,  7,  6,  7,  8,  9,
     33  4, 5, 6, 7, 6, 7, 8, 9, 8, 9, 10, 11, 10, 11, 12, 13
     34 };
     35 // clang-format on
     36 
     37 static inline int16x4_t convolve8_4_h(const uint8x8_t s0, const uint8x8_t s1,
     38                                      const uint8x8_t s2, const uint8x8_t s3,
     39                                      const int8x8_t filter,
     40                                      const int32x4_t horiz_const) {
     41  const int8x16_t filters = vcombine_s8(filter, filter);
     42 
     43  uint8x16_t s01 = vcombine_u8(s0, s1);
     44  uint8x16_t s23 = vcombine_u8(s2, s3);
     45 
     46  // Transform sample range to [-128, 127] for 8-bit signed dot product.
     47  int8x16_t s01_128 = vreinterpretq_s8_u8(vsubq_u8(s01, vdupq_n_u8(128)));
     48  int8x16_t s23_128 = vreinterpretq_s8_u8(vsubq_u8(s23, vdupq_n_u8(128)));
     49 
     50  int32x4_t sum01 = vdotq_s32(horiz_const, s01_128, filters);
     51  int32x4_t sum23 = vdotq_s32(horiz_const, s23_128, filters);
     52 
     53  int32x4_t sum = vpaddq_s32(sum01, sum23);
     54 
     55  // We halved the filter values so -1 from right shift.
     56  return vshrn_n_s32(sum, ROUND0_BITS - 1);
     57 }
     58 
     59 static inline int16x8_t convolve8_8_h(const uint8x8_t s0, const uint8x8_t s1,
     60                                      const uint8x8_t s2, const uint8x8_t s3,
     61                                      const uint8x8_t s4, const uint8x8_t s5,
     62                                      const uint8x8_t s6, const uint8x8_t s7,
     63                                      const int8x8_t filter,
     64                                      const int32x4_t horiz_const) {
     65  const int8x16_t filters = vcombine_s8(filter, filter);
     66 
     67  uint8x16_t s01 = vcombine_u8(s0, s1);
     68  uint8x16_t s23 = vcombine_u8(s2, s3);
     69  uint8x16_t s45 = vcombine_u8(s4, s5);
     70  uint8x16_t s67 = vcombine_u8(s6, s7);
     71 
     72  // Transform sample range to [-128, 127] for 8-bit signed dot product.
     73  int8x16_t s01_128 = vreinterpretq_s8_u8(vsubq_u8(s01, vdupq_n_u8(128)));
     74  int8x16_t s23_128 = vreinterpretq_s8_u8(vsubq_u8(s23, vdupq_n_u8(128)));
     75  int8x16_t s45_128 = vreinterpretq_s8_u8(vsubq_u8(s45, vdupq_n_u8(128)));
     76  int8x16_t s67_128 = vreinterpretq_s8_u8(vsubq_u8(s67, vdupq_n_u8(128)));
     77 
     78  int32x4_t sum01 = vdotq_s32(horiz_const, s01_128, filters);
     79  int32x4_t sum23 = vdotq_s32(horiz_const, s23_128, filters);
     80  int32x4_t sum45 = vdotq_s32(horiz_const, s45_128, filters);
     81  int32x4_t sum67 = vdotq_s32(horiz_const, s67_128, filters);
     82 
     83  int32x4_t sum0123 = vpaddq_s32(sum01, sum23);
     84  int32x4_t sum4567 = vpaddq_s32(sum45, sum67);
     85 
     86  // We halved the filter values so -1 from right shift.
     87  return vcombine_s16(vshrn_n_s32(sum0123, ROUND0_BITS - 1),
     88                      vshrn_n_s32(sum4567, ROUND0_BITS - 1));
     89 }
     90 
     91 static inline void convolve_horiz_scale_neon_dotprod(
     92    const uint8_t *src, int src_stride, int16_t *dst, int dst_stride, int w,
     93    int h, const int16_t *x_filter, const int subpel_x_qn,
     94    const int x_step_qn) {
     95  DECLARE_ALIGNED(16, int16_t, temp[8 * 8]);
     96  const int bd = 8;
     97  // A shim of 1 << (ROUND0_BITS - 1) enables us to use non-rounding
     98  // shifts - which are generally faster than rounding shifts on modern CPUs.
     99  const int32_t horiz_offset =
    100      (1 << (bd + FILTER_BITS - 1)) + (1 << (ROUND0_BITS - 1));
    101  // The shim of 128 << FILTER_BITS is needed because we are subtracting 128
    102  // from every source value.
    103  const int32_t dotprod_offset = 128 << FILTER_BITS;
    104  // Divide the total by 4: we halved the filter values and will use a pairwise
    105  // add in the convolution kernel.
    106  const int32x4_t horiz_offset_vec =
    107      vdupq_n_s32((horiz_offset + dotprod_offset) >> 2);
    108 
    109  if (w == 4) {
    110    do {
    111      int x_qn = subpel_x_qn;
    112 
    113      // Process a 4x4 tile.
    114      for (int r = 0; r < 4; r++) {
    115        const uint8_t *const s = &src[x_qn >> SCALE_SUBPEL_BITS];
    116 
    117        const ptrdiff_t filter_offset =
    118            SUBPEL_TAPS * ((x_qn & SCALE_SUBPEL_MASK) >> SCALE_EXTRA_BITS);
    119        // Filter values are all even so halve them to fit in int8_t.
    120        const int8x8_t filter =
    121            vshrn_n_s16(vld1q_s16(x_filter + filter_offset), 1);
    122 
    123        uint8x8_t t0, t1, t2, t3;
    124        load_u8_8x4(s, src_stride, &t0, &t1, &t2, &t3);
    125 
    126        int16x4_t d0 = convolve8_4_h(t0, t1, t2, t3, filter, horiz_offset_vec);
    127 
    128        vst1_s16(&temp[r * 4], d0);
    129 
    130        x_qn += x_step_qn;
    131      }
    132 
    133      // Transpose the 4x4 result tile and store.
    134      int16x4_t d0, d1, d2, d3;
    135      load_s16_4x4(temp, 4, &d0, &d1, &d2, &d3);
    136 
    137      transpose_elems_inplace_s16_4x4(&d0, &d1, &d2, &d3);
    138 
    139      store_s16_4x4(dst, dst_stride, d0, d1, d2, d3);
    140 
    141      dst += 4 * dst_stride;
    142      src += 4 * src_stride;
    143      h -= 4;
    144    } while (h > 0);
    145  } else {
    146    do {
    147      int x_qn = subpel_x_qn;
    148      int16_t *d = dst;
    149      int width = w;
    150 
    151      do {
    152        // Process an 8x8 tile.
    153        for (int r = 0; r < 8; r++) {
    154          const uint8_t *const s = &src[(x_qn >> SCALE_SUBPEL_BITS)];
    155 
    156          const ptrdiff_t filter_offset =
    157              SUBPEL_TAPS * ((x_qn & SCALE_SUBPEL_MASK) >> SCALE_EXTRA_BITS);
    158          // Filter values are all even so halve them to fit in int8_t.
    159          int8x8_t filter = vshrn_n_s16(vld1q_s16(x_filter + filter_offset), 1);
    160 
    161          uint8x8_t t0, t1, t2, t3, t4, t5, t6, t7;
    162          load_u8_8x8(s, src_stride, &t0, &t1, &t2, &t3, &t4, &t5, &t6, &t7);
    163 
    164          int16x8_t d0 = convolve8_8_h(t0, t1, t2, t3, t4, t5, t6, t7, filter,
    165                                       horiz_offset_vec);
    166 
    167          vst1q_s16(&temp[r * 8], d0);
    168 
    169          x_qn += x_step_qn;
    170        }
    171 
    172        // Transpose the 8x8 result tile and store.
    173        int16x8_t d0, d1, d2, d3, d4, d5, d6, d7;
    174        load_s16_8x8(temp, 8, &d0, &d1, &d2, &d3, &d4, &d5, &d6, &d7);
    175 
    176        transpose_elems_inplace_s16_8x8(&d0, &d1, &d2, &d3, &d4, &d5, &d6, &d7);
    177 
    178        store_s16_8x8(d, dst_stride, d0, d1, d2, d3, d4, d5, d6, d7);
    179 
    180        d += 8;
    181        width -= 8;
    182      } while (width != 0);
    183 
    184      dst += 8 * dst_stride;
    185      src += 8 * src_stride;
    186      h -= 8;
    187    } while (h > 0);
    188  }
    189 }
    190 
    191 static inline int16x4_t convolve8_4_h_scale_2(uint8x16_t samples,
    192                                              const int8x8_t filters,
    193                                              const int32x4_t horiz_const,
    194                                              const uint8x16x2_t permute_tbl) {
    195  // Transform sample range to [-128, 127] for 8-bit signed dot product.
    196  int8x16_t samples_128 =
    197      vreinterpretq_s8_u8(vsubq_u8(samples, vdupq_n_u8(128)));
    198 
    199  // Permute samples ready for dot product.
    200  // { 0, 1, 2, 3, 2, 3, 4, 5, 4, 5,  6,  7,  6,  7,  8,  9 }
    201  // { 4, 5, 6, 7, 6, 7, 8, 9, 8, 9, 10, 11, 10, 11, 12, 13 }
    202  int8x16_t perm_samples[2] = { vqtbl1q_s8(samples_128, permute_tbl.val[0]),
    203                                vqtbl1q_s8(samples_128, permute_tbl.val[1]) };
    204 
    205  int32x4_t sum = vdotq_lane_s32(horiz_const, perm_samples[0], filters, 0);
    206  sum = vdotq_lane_s32(sum, perm_samples[1], filters, 1);
    207 
    208  // We halved the filter values so -1 from right shift.
    209  return vshrn_n_s32(sum, ROUND0_BITS - 1);
    210 }
    211 
    212 static inline int16x8_t convolve8_8_h_scale_2(uint8x16_t samples[2],
    213                                              const int8x8_t filters,
    214                                              const int32x4_t horiz_const,
    215                                              const uint8x16x2_t permute_tbl) {
    216  // Transform sample range to [-128, 127] for 8-bit signed dot product.
    217  int8x16_t samples0_128 =
    218      vreinterpretq_s8_u8(vsubq_u8(samples[0], vdupq_n_u8(128)));
    219  int8x16_t samples1_128 =
    220      vreinterpretq_s8_u8(vsubq_u8(samples[1], vdupq_n_u8(128)));
    221 
    222  // Permute samples ready for dot product.
    223  // { 0, 1, 2, 3, 2, 3, 4, 5, 4, 5,  6,  7,  6,  7,  8,  9 }
    224  // { 4, 5, 6, 7, 6, 7, 8, 9, 8, 9, 10, 11, 10, 11, 12, 13 }
    225  int8x16_t perm_samples[4] = { vqtbl1q_s8(samples0_128, permute_tbl.val[0]),
    226                                vqtbl1q_s8(samples0_128, permute_tbl.val[1]),
    227                                vqtbl1q_s8(samples1_128, permute_tbl.val[0]),
    228                                vqtbl1q_s8(samples1_128, permute_tbl.val[1]) };
    229 
    230  // First 4 output values.
    231  int32x4_t sum0123 = vdotq_lane_s32(horiz_const, perm_samples[0], filters, 0);
    232  sum0123 = vdotq_lane_s32(sum0123, perm_samples[1], filters, 1);
    233  // Second 4 output values.
    234  int32x4_t sum4567 = vdotq_lane_s32(horiz_const, perm_samples[2], filters, 0);
    235  sum4567 = vdotq_lane_s32(sum4567, perm_samples[3], filters, 1);
    236 
    237  // We halved the filter values so -1 from right shift.
    238  return vcombine_s16(vshrn_n_s32(sum0123, ROUND0_BITS - 1),
    239                      vshrn_n_s32(sum4567, ROUND0_BITS - 1));
    240 }
    241 
    242 static inline void convolve_horiz_scale_2_neon_dotprod(
    243    const uint8_t *src, int src_stride, int16_t *dst, int dst_stride, int w,
    244    int h, const int16_t *x_filter) {
    245  const int bd = 8;
    246  // A shim of 1 << (ROUND0_BITS - 1) enables us to use non-rounding
    247  // shifts - which are generally faster than rounding shifts on modern CPUs.
    248  const int32_t horiz_offset =
    249      (1 << (bd + FILTER_BITS - 1)) + (1 << (ROUND0_BITS - 1));
    250  // The shim of 128 << FILTER_BITS is needed because we are subtracting 128
    251  // from every source value.
    252  const int32_t dotprod_offset = 128 << FILTER_BITS;
    253  // Divide the total by 2 because we halved the filter values.
    254  const int32x4_t horiz_offset_vec =
    255      vdupq_n_s32((horiz_offset + dotprod_offset) >> 1);
    256 
    257  const uint8x16x2_t permute_tbl = vld1q_u8_x2(kScale2DotProdPermuteTbl);
    258  // Filter values are all even so halve them to fit in int8_t.
    259  const int8x8_t filter = vshrn_n_s16(vld1q_s16(x_filter), 1);
    260 
    261  if (w == 4) {
    262    do {
    263      const uint8_t *s = src;
    264      int16_t *d = dst;
    265      int width = w;
    266 
    267      do {
    268        uint8x16_t s0, s1, s2, s3;
    269        load_u8_16x4(s, src_stride, &s0, &s1, &s2, &s3);
    270 
    271        int16x4_t d0 =
    272            convolve8_4_h_scale_2(s0, filter, horiz_offset_vec, permute_tbl);
    273        int16x4_t d1 =
    274            convolve8_4_h_scale_2(s1, filter, horiz_offset_vec, permute_tbl);
    275        int16x4_t d2 =
    276            convolve8_4_h_scale_2(s2, filter, horiz_offset_vec, permute_tbl);
    277        int16x4_t d3 =
    278            convolve8_4_h_scale_2(s3, filter, horiz_offset_vec, permute_tbl);
    279 
    280        store_s16_4x4(d, dst_stride, d0, d1, d2, d3);
    281 
    282        s += 8;
    283        d += 4;
    284        width -= 4;
    285      } while (width != 0);
    286 
    287      dst += 4 * dst_stride;
    288      src += 4 * src_stride;
    289      h -= 4;
    290    } while (h > 0);
    291  } else {
    292    do {
    293      const uint8_t *s = src;
    294      int16_t *d = dst;
    295      int width = w;
    296 
    297      do {
    298        uint8x16_t s0[2], s1[2], s2[2], s3[2];
    299        load_u8_16x4(s, src_stride, &s0[0], &s1[0], &s2[0], &s3[0]);
    300        load_u8_16x4(s + 8, src_stride, &s0[1], &s1[1], &s2[1], &s3[1]);
    301 
    302        int16x8_t d0 =
    303            convolve8_8_h_scale_2(s0, filter, horiz_offset_vec, permute_tbl);
    304        int16x8_t d1 =
    305            convolve8_8_h_scale_2(s1, filter, horiz_offset_vec, permute_tbl);
    306        int16x8_t d2 =
    307            convolve8_8_h_scale_2(s2, filter, horiz_offset_vec, permute_tbl);
    308        int16x8_t d3 =
    309            convolve8_8_h_scale_2(s3, filter, horiz_offset_vec, permute_tbl);
    310 
    311        store_s16_8x4(d, dst_stride, d0, d1, d2, d3);
    312 
    313        s += 16;
    314        d += 8;
    315        width -= 8;
    316      } while (width != 0);
    317 
    318      dst += 4 * dst_stride;
    319      src += 4 * src_stride;
    320      h -= 4;
    321    } while (h > 0);
    322  }
    323 }
    324 
    325 void av1_convolve_2d_scale_neon_dotprod(
    326    const uint8_t *src, int src_stride, uint8_t *dst, int dst_stride, int w,
    327    int h, const InterpFilterParams *filter_params_x,
    328    const InterpFilterParams *filter_params_y, const int subpel_x_qn,
    329    const int x_step_qn, const int subpel_y_qn, const int y_step_qn,
    330    ConvolveParams *conv_params) {
    331  if (w < 4 || h < 4) {
    332    av1_convolve_2d_scale_c(src, src_stride, dst, dst_stride, w, h,
    333                            filter_params_x, filter_params_y, subpel_x_qn,
    334                            x_step_qn, subpel_y_qn, y_step_qn, conv_params);
    335    return;
    336  }
    337 
    338  // For the interpolation 8-tap filters are used.
    339  assert(filter_params_y->taps <= 8 && filter_params_x->taps <= 8);
    340 
    341  DECLARE_ALIGNED(32, int16_t,
    342                  im_block[(2 * MAX_SB_SIZE + MAX_FILTER_TAP) * MAX_SB_SIZE]);
    343  int im_h = (((h - 1) * y_step_qn + subpel_y_qn) >> SCALE_SUBPEL_BITS) +
    344             filter_params_y->taps;
    345  int im_stride = MAX_SB_SIZE;
    346  CONV_BUF_TYPE *dst16 = conv_params->dst;
    347  const int dst16_stride = conv_params->dst_stride;
    348 
    349  // Account for needing filter_taps / 2 - 1 lines prior and filter_taps / 2
    350  // lines post both horizontally and vertically.
    351  const ptrdiff_t horiz_offset = filter_params_x->taps / 2 - 1;
    352  const ptrdiff_t vert_offset = (filter_params_y->taps / 2 - 1) * src_stride;
    353 
    354  // Horizontal filter
    355  if (x_step_qn != 2 * (1 << SCALE_SUBPEL_BITS)) {
    356    convolve_horiz_scale_neon_dotprod(
    357        src - horiz_offset - vert_offset, src_stride, im_block, im_stride, w,
    358        im_h, filter_params_x->filter_ptr, subpel_x_qn, x_step_qn);
    359  } else {
    360    assert(subpel_x_qn < (1 << SCALE_SUBPEL_BITS));
    361    // The filter index is calculated using the
    362    // ((subpel_x_qn + x * x_step_qn) & SCALE_SUBPEL_MASK) >> SCALE_EXTRA_BITS
    363    // equation, where the values of x are from 0 to w. If x_step_qn is a
    364    // multiple of SCALE_SUBPEL_MASK we can leave it out of the equation.
    365    const ptrdiff_t filter_offset =
    366        SUBPEL_TAPS * ((subpel_x_qn & SCALE_SUBPEL_MASK) >> SCALE_EXTRA_BITS);
    367    const int16_t *x_filter = filter_params_x->filter_ptr + filter_offset;
    368 
    369    // The source index is calculated using the (subpel_x_qn + x * x_step_qn) >>
    370    // SCALE_SUBPEL_BITS, where the values of x are from 0 to w. If subpel_x_qn
    371    // < (1 << SCALE_SUBPEL_BITS) and x_step_qn % (1 << SCALE_SUBPEL_BITS) == 0,
    372    // the source index can be determined using the value x * (x_step_qn /
    373    // (1 << SCALE_SUBPEL_BITS)).
    374    convolve_horiz_scale_2_neon_dotprod(src - horiz_offset - vert_offset,
    375                                        src_stride, im_block, im_stride, w,
    376                                        im_h, x_filter);
    377  }
    378 
    379  // Vertical filter
    380  if (filter_params_y->interp_filter == MULTITAP_SHARP) {
    381    if (UNLIKELY(conv_params->is_compound)) {
    382      if (conv_params->do_average) {
    383        if (conv_params->use_dist_wtd_comp_avg) {
    384          compound_dist_wtd_convolve_vert_scale_8tap_neon(
    385              im_block, im_stride, dst, dst_stride, dst16, dst16_stride, w, h,
    386              filter_params_y->filter_ptr, conv_params, subpel_y_qn, y_step_qn);
    387        } else {
    388          compound_avg_convolve_vert_scale_8tap_neon(
    389              im_block, im_stride, dst, dst_stride, dst16, dst16_stride, w, h,
    390              filter_params_y->filter_ptr, subpel_y_qn, y_step_qn);
    391        }
    392      } else {
    393        compound_convolve_vert_scale_8tap_neon(
    394            im_block, im_stride, dst16, dst16_stride, w, h,
    395            filter_params_y->filter_ptr, subpel_y_qn, y_step_qn);
    396      }
    397    } else {
    398      convolve_vert_scale_8tap_neon(im_block, im_stride, dst, dst_stride, w, h,
    399                                    filter_params_y->filter_ptr, subpel_y_qn,
    400                                    y_step_qn);
    401    }
    402  } else {
    403    if (UNLIKELY(conv_params->is_compound)) {
    404      if (conv_params->do_average) {
    405        if (conv_params->use_dist_wtd_comp_avg) {
    406          compound_dist_wtd_convolve_vert_scale_6tap_neon(
    407              im_block + im_stride, im_stride, dst, dst_stride, dst16,
    408              dst16_stride, w, h, filter_params_y->filter_ptr, conv_params,
    409              subpel_y_qn, y_step_qn);
    410        } else {
    411          compound_avg_convolve_vert_scale_6tap_neon(
    412              im_block + im_stride, im_stride, dst, dst_stride, dst16,
    413              dst16_stride, w, h, filter_params_y->filter_ptr, subpel_y_qn,
    414              y_step_qn);
    415        }
    416      } else {
    417        compound_convolve_vert_scale_6tap_neon(
    418            im_block + im_stride, im_stride, dst16, dst16_stride, w, h,
    419            filter_params_y->filter_ptr, subpel_y_qn, y_step_qn);
    420      }
    421    } else {
    422      convolve_vert_scale_6tap_neon(
    423          im_block + im_stride, im_stride, dst, dst_stride, w, h,
    424          filter_params_y->filter_ptr, subpel_y_qn, y_step_qn);
    425    }
    426  }
    427 }