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/*
* Copyright (c) 2023, Alliance for Open Media. All rights reserved.
*
* This source code is subject to the terms of the BSD 2 Clause License and
* the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
* was not distributed with this source code in the LICENSE file, you can
* obtain it at www.aomedia.org/license/software. If the Alliance for Open
* Media Patent License 1.0 was not distributed with this source code in the
* PATENTS file, you can obtain it at www.aomedia.org/license/patent.
*/
#include <arm_neon.h>
#include "aom_dsp/arm/sum_neon.h"
#include "config/aom_config.h"
#include "config/av1_rtcd.h"
static int32x4_t k_means_multiply_add_neon(const int16x8_t a) {
const int32x4_t l = vmull_s16(vget_low_s16(a), vget_low_s16(a));
const int32x4_t h = vmull_s16(vget_high_s16(a), vget_high_s16(a));
#if AOM_ARCH_AARCH64
return vpaddq_s32(l, h);
#else
const int32x2_t dl = vpadd_s32(vget_low_s32(l), vget_high_s32(l));
const int32x2_t dh = vpadd_s32(vget_low_s32(h), vget_high_s32(h));
return vcombine_s32(dl, dh);
#endif
}
void av1_calc_indices_dim1_neon(const int16_t *data, const int16_t *centroids,
uint8_t *indices, int64_t *total_dist, int n,
int k) {
int64x2_t sum = vdupq_n_s64(0);
int16x8_t cents[PALETTE_MAX_SIZE];
for (int j = 0; j < k; ++j) {
cents[j] = vdupq_n_s16(centroids[j]);
}
for (int i = 0; i < n; i += 8) {
const int16x8_t in = vld1q_s16(data);
uint16x8_t ind = vdupq_n_u16(0);
// Compute the distance to the first centroid.
int16x8_t dist_min = vabdq_s16(in, cents[0]);
for (int j = 1; j < k; ++j) {
// Compute the distance to the centroid.
const int16x8_t dist = vabdq_s16(in, cents[j]);
// Compare to the minimal one.
const uint16x8_t cmp = vcgtq_s16(dist_min, dist);
dist_min = vminq_s16(dist_min, dist);
const uint16x8_t ind1 = vdupq_n_u16(j);
ind = vbslq_u16(cmp, ind1, ind);
}
if (total_dist) {
// Square, convert to 32 bit and add together.
const int32x4_t l =
vmull_s16(vget_low_s16(dist_min), vget_low_s16(dist_min));
const int32x4_t sum32_tmp =
vmlal_s16(l, vget_high_s16(dist_min), vget_high_s16(dist_min));
// Pairwise sum, convert to 64 bit and add to sum.
sum = vpadalq_s32(sum, sum32_tmp);
}
vst1_u8(indices, vmovn_u16(ind));
indices += 8;
data += 8;
}
if (total_dist) {
*total_dist = horizontal_add_s64x2(sum);
}
}
void av1_calc_indices_dim2_neon(const int16_t *data, const int16_t *centroids,
uint8_t *indices, int64_t *total_dist, int n,
int k) {
int64x2_t sum = vdupq_n_s64(0);
uint32x4_t ind[2];
int16x8_t cents[PALETTE_MAX_SIZE];
for (int j = 0; j < k; ++j) {
const int16_t cx = centroids[2 * j], cy = centroids[2 * j + 1];
const int16_t cxcy[8] = { cx, cy, cx, cy, cx, cy, cx, cy };
cents[j] = vld1q_s16(cxcy);
}
for (int i = 0; i < n; i += 8) {
for (int l = 0; l < 2; ++l) {
const int16x8_t in = vld1q_s16(data);
ind[l] = vdupq_n_u32(0);
// Compute the distance to the first centroid.
int16x8_t d1 = vsubq_s16(in, cents[0]);
int32x4_t dist_min = k_means_multiply_add_neon(d1);
for (int j = 1; j < k; ++j) {
// Compute the distance to the centroid.
d1 = vsubq_s16(in, cents[j]);
const int32x4_t dist = k_means_multiply_add_neon(d1);
// Compare to the minimal one.
const uint32x4_t cmp = vcgtq_s32(dist_min, dist);
dist_min = vminq_s32(dist_min, dist);
const uint32x4_t ind1 = vdupq_n_u32(j);
ind[l] = vbslq_u32(cmp, ind1, ind[l]);
}
if (total_dist) {
// Pairwise sum, convert to 64 bit and add to sum.
sum = vpadalq_s32(sum, dist_min);
}
data += 8;
}
// Cast to 8 bit and store.
vst1_u8(indices,
vmovn_u16(vcombine_u16(vmovn_u32(ind[0]), vmovn_u32(ind[1]))));
indices += 8;
}
if (total_dist) {
*total_dist = horizontal_add_s64x2(sum);
}
}