1 files changed, 79 insertions, 0 deletions
diff --git a/aom_dsp/flow_estimation/x86/corner_match_avx2.c b/aom_dsp/flow_estimation/x86/corner_match_avx2.c
new file mode 100644
index 000000000..9830ad820
--- /dev/null
+++ b/aom_dsp/flow_estimation/x86/corner_match_avx2.c
@@ -0,0 +1,79 @@
+/*
+ * Copyright (c) 2018, 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 <math.h>
+
+#include <immintrin.h>
+#include "config/aom_dsp_rtcd.h"
+
+#include "aom_ports/mem.h"
+#include "aom_dsp/flow_estimation/corner_match.h"
+
+DECLARE_ALIGNED(16, static const uint8_t,
+                byte_mask[16]) = { 255, 255, 255, 255, 255, 255, 255, 255,
+                                   255, 255, 255, 255, 255, 0,   0,   0 };
+#if MATCH_SZ != 13
+#error "Need to change byte_mask in corner_match_sse4.c if MATCH_SZ != 13"
+#endif
+
+/* Compute corr(im1, im2) * MATCH_SZ * stddev(im1), where the
+correlation/standard deviation are taken over MATCH_SZ by MATCH_SZ windows
+of each image, centered at (x1, y1) and (x2, y2) respectively.
+*/
+double av1_compute_cross_correlation_avx2(unsigned char *im1, int stride1,
+                                          int x1, int y1, unsigned char *im2,
+                                          int stride2, int x2, int y2) {
+  int i, stride1_i = 0, stride2_i = 0;
+  __m256i temp1, sum_vec, sumsq2_vec, cross_vec, v, v1_1, v2_1;
+  const __m128i mask = _mm_load_si128((__m128i *)byte_mask);
+  const __m256i zero = _mm256_setzero_si256();
+  __m128i v1, v2;
+
+  sum_vec = zero;
+  sumsq2_vec = zero;
+  cross_vec = zero;
+
+  im1 += (y1 - MATCH_SZ_BY2) * stride1 + (x1 - MATCH_SZ_BY2);
+  im2 += (y2 - MATCH_SZ_BY2) * stride2 + (x2 - MATCH_SZ_BY2);
+
+  for (i = 0; i < MATCH_SZ; ++i) {
+    v1 = _mm_and_si128(_mm_loadu_si128((__m128i *)&im1[stride1_i]), mask);
+    v1_1 = _mm256_cvtepu8_epi16(v1);
+    v2 = _mm_and_si128(_mm_loadu_si128((__m128i *)&im2[stride2_i]), mask);
+    v2_1 = _mm256_cvtepu8_epi16(v2);
+
+    v = _mm256_insertf128_si256(_mm256_castsi128_si256(v1), v2, 1);
+    sumsq2_vec = _mm256_add_epi32(sumsq2_vec, _mm256_madd_epi16(v2_1, v2_1));
+
+    sum_vec = _mm256_add_epi16(sum_vec, _mm256_sad_epu8(v, zero));
+    cross_vec = _mm256_add_epi32(cross_vec, _mm256_madd_epi16(v1_1, v2_1));
+    stride1_i += stride1;
+    stride2_i += stride2;
+  }
+  __m256i sum_vec1 = _mm256_srli_si256(sum_vec, 8);
+  sum_vec = _mm256_add_epi32(sum_vec, sum_vec1);
+  int sum1_acc = _mm_cvtsi128_si32(_mm256_castsi256_si128(sum_vec));
+  int sum2_acc = _mm256_extract_epi32(sum_vec, 4);
+
+  __m256i unp_low = _mm256_unpacklo_epi64(sumsq2_vec, cross_vec);
+  __m256i unp_hig = _mm256_unpackhi_epi64(sumsq2_vec, cross_vec);
+  temp1 = _mm256_add_epi32(unp_low, unp_hig);
+
+  __m128i low_sumsq = _mm256_castsi256_si128(temp1);
+  low_sumsq = _mm_add_epi32(low_sumsq, _mm256_extractf128_si256(temp1, 1));
+  low_sumsq = _mm_add_epi32(low_sumsq, _mm_srli_epi64(low_sumsq, 32));
+  int sumsq2_acc = _mm_cvtsi128_si32(low_sumsq);
+  int cross_acc = _mm_extract_epi32(low_sumsq, 2);
+
+  int var2 = sumsq2_acc * MATCH_SZ_SQ - sum2_acc * sum2_acc;
+  int cov = cross_acc * MATCH_SZ_SQ - sum1_acc * sum2_acc;
+  return cov / sqrt((double)var2);
+}