1 files changed, 132 insertions, 0 deletions
diff --git a/third_party/aom/av1/encoder/x86/av1_k_means_avx2.c b/third_party/aom/av1/encoder/x86/av1_k_means_avx2.c
new file mode 100644
index 0000000000..52ddc66437
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+++ b/third_party/aom/av1/encoder/x86/av1_k_means_avx2.c
@@ -0,0 +1,132 @@
+/*
+ * Copyright (c) 2020, 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 <immintrin.h>  // AVX2
+
+#include "config/av1_rtcd.h"
+#include "aom_dsp/x86/synonyms.h"
+
+static int64_t k_means_horizontal_sum_avx2(__m256i a) {
+  const __m128i low = _mm256_castsi256_si128(a);
+  const __m128i high = _mm256_extracti128_si256(a, 1);
+  const __m128i sum = _mm_add_epi64(low, high);
+  const __m128i sum_high = _mm_unpackhi_epi64(sum, sum);
+  int64_t res;
+  _mm_storel_epi64((__m128i *)&res, _mm_add_epi64(sum, sum_high));
+  return res;
+}
+
+void av1_calc_indices_dim1_avx2(const int16_t *data, const int16_t *centroids,
+                                uint8_t *indices, int64_t *total_dist, int n,
+                                int k) {
+  const __m256i v_zero = _mm256_setzero_si256();
+  __m256i sum = _mm256_setzero_si256();
+  __m256i cents[PALETTE_MAX_SIZE];
+  for (int j = 0; j < k; ++j) {
+    cents[j] = _mm256_set1_epi16(centroids[j]);
+  }
+
+  for (int i = 0; i < n; i += 16) {
+    const __m256i in = _mm256_loadu_si256((__m256i *)data);
+    __m256i ind = _mm256_setzero_si256();
+    // Compute the distance to the first centroid.
+    __m256i d1 = _mm256_sub_epi16(in, cents[0]);
+    __m256i dist_min = _mm256_abs_epi16(d1);
+
+    for (int j = 1; j < k; ++j) {
+      // Compute the distance to the centroid.
+      d1 = _mm256_sub_epi16(in, cents[j]);
+      const __m256i dist = _mm256_abs_epi16(d1);
+      // Compare to the minimal one.
+      const __m256i cmp = _mm256_cmpgt_epi16(dist_min, dist);
+      dist_min = _mm256_min_epi16(dist_min, dist);
+      const __m256i ind1 = _mm256_set1_epi16(j);
+      ind = _mm256_or_si256(_mm256_andnot_si256(cmp, ind),
+                            _mm256_and_si256(cmp, ind1));
+    }
+
+    const __m256i p1 = _mm256_packus_epi16(ind, v_zero);
+    const __m256i px = _mm256_permute4x64_epi64(p1, 0x58);
+    const __m128i d2 = _mm256_extracti128_si256(px, 0);
+
+    _mm_storeu_si128((__m128i *)indices, d2);
+
+    if (total_dist) {
+      // Square, convert to 32 bit and add together.
+      dist_min = _mm256_madd_epi16(dist_min, dist_min);
+      // Convert to 64 bit and add to sum.
+      const __m256i dist1 = _mm256_unpacklo_epi32(dist_min, v_zero);
+      const __m256i dist2 = _mm256_unpackhi_epi32(dist_min, v_zero);
+      sum = _mm256_add_epi64(sum, dist1);
+      sum = _mm256_add_epi64(sum, dist2);
+    }
+
+    indices += 16;
+    data += 16;
+  }
+  if (total_dist) {
+    *total_dist = k_means_horizontal_sum_avx2(sum);
+  }
+}
+
+void av1_calc_indices_dim2_avx2(const int16_t *data, const int16_t *centroids,
+                                uint8_t *indices, int64_t *total_dist, int n,
+                                int k) {
+  const __m256i v_zero = _mm256_setzero_si256();
+  const __m256i permute = _mm256_set_epi32(0, 0, 0, 0, 5, 1, 4, 0);
+  __m256i sum = _mm256_setzero_si256();
+  __m256i ind[2];
+  __m256i cents[PALETTE_MAX_SIZE];
+  for (int j = 0; j < k; ++j) {
+    const int16_t cx = centroids[2 * j], cy = centroids[2 * j + 1];
+    cents[j] = _mm256_set_epi16(cy, cx, cy, cx, cy, cx, cy, cx, cy, cx, cy, cx,
+                                cy, cx, cy, cx);
+  }
+
+  for (int i = 0; i < n; i += 16) {
+    for (int l = 0; l < 2; ++l) {
+      const __m256i in = _mm256_loadu_si256((__m256i *)data);
+      ind[l] = _mm256_setzero_si256();
+      // Compute the distance to the first centroid.
+      __m256i d1 = _mm256_sub_epi16(in, cents[0]);
+      __m256i dist_min = _mm256_madd_epi16(d1, d1);
+
+      for (int j = 1; j < k; ++j) {
+        // Compute the distance to the centroid.
+        d1 = _mm256_sub_epi16(in, cents[j]);
+        const __m256i dist = _mm256_madd_epi16(d1, d1);
+        // Compare to the minimal one.
+        const __m256i cmp = _mm256_cmpgt_epi32(dist_min, dist);
+        dist_min = _mm256_min_epi32(dist_min, dist);
+        const __m256i ind1 = _mm256_set1_epi32(j);
+        ind[l] = _mm256_or_si256(_mm256_andnot_si256(cmp, ind[l]),
+                                 _mm256_and_si256(cmp, ind1));
+      }
+      if (total_dist) {
+        // Convert to 64 bit and add to sum.
+        const __m256i dist1 = _mm256_unpacklo_epi32(dist_min, v_zero);
+        const __m256i dist2 = _mm256_unpackhi_epi32(dist_min, v_zero);
+        sum = _mm256_add_epi64(sum, dist1);
+        sum = _mm256_add_epi64(sum, dist2);
+      }
+      data += 16;
+    }
+    // Cast to 8 bit and store.
+    const __m256i d2 = _mm256_packus_epi32(ind[0], ind[1]);
+    const __m256i d3 = _mm256_packus_epi16(d2, v_zero);
+    const __m256i d4 = _mm256_permutevar8x32_epi32(d3, permute);
+    const __m128i d5 = _mm256_extracti128_si256(d4, 0);
+    _mm_storeu_si128((__m128i *)indices, d5);
+    indices += 16;
+  }
+  if (total_dist) {
+    *total_dist = k_means_horizontal_sum_avx2(sum);
+  }
+}