1 files changed, 103 insertions, 0 deletions
diff --git a/third_party/aom/av1/encoder/x86/corner_match_sse4.c b/third_party/aom/av1/encoder/x86/corner_match_sse4.c
new file mode 100644
index 0000000000..93f37b71d3
--- /dev/null
+++ b/third_party/aom/av1/encoder/x86/corner_match_sse4.c
@@ -0,0 +1,103 @@
+/*
+ * 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 <stdlib.h>
+#include <memory.h>
+#include <math.h>
+#include <assert.h>
+
+#include <smmintrin.h>
+
+#include "config/av1_rtcd.h"
+
+#include "aom_ports/mem.h"
+#include "av1/encoder/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 compute_cross_correlation_sse4_1(unsigned char *im1, int stride1, int x1,
+                                        int y1, unsigned char *im2, int stride2,
+                                        int x2, int y2) {
+  int i;
+  // 2 16-bit partial sums in lanes 0, 4 (== 2 32-bit partial sums in lanes 0,
+  // 2)
+  __m128i sum1_vec = _mm_setzero_si128();
+  __m128i sum2_vec = _mm_setzero_si128();
+  // 4 32-bit partial sums of squares
+  __m128i sumsq2_vec = _mm_setzero_si128();
+  __m128i cross_vec = _mm_setzero_si128();
+
+  const __m128i mask = _mm_load_si128((__m128i *)byte_mask);
+  const __m128i zero = _mm_setzero_si128();
+
+  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) {
+    const __m128i v1 =
+        _mm_and_si128(_mm_loadu_si128((__m128i *)&im1[i * stride1]), mask);
+    const __m128i v2 =
+        _mm_and_si128(_mm_loadu_si128((__m128i *)&im2[i * stride2]), mask);
+
+    // Using the 'sad' intrinsic here is a bit faster than adding
+    // v1_l + v1_r and v2_l + v2_r, plus it avoids the need for a 16->32 bit
+    // conversion step later, for a net speedup of ~10%
+    sum1_vec = _mm_add_epi16(sum1_vec, _mm_sad_epu8(v1, zero));
+    sum2_vec = _mm_add_epi16(sum2_vec, _mm_sad_epu8(v2, zero));
+
+    const __m128i v1_l = _mm_cvtepu8_epi16(v1);
+    const __m128i v1_r = _mm_cvtepu8_epi16(_mm_srli_si128(v1, 8));
+    const __m128i v2_l = _mm_cvtepu8_epi16(v2);
+    const __m128i v2_r = _mm_cvtepu8_epi16(_mm_srli_si128(v2, 8));
+
+    sumsq2_vec = _mm_add_epi32(
+        sumsq2_vec,
+        _mm_add_epi32(_mm_madd_epi16(v2_l, v2_l), _mm_madd_epi16(v2_r, v2_r)));
+    cross_vec = _mm_add_epi32(
+        cross_vec,
+        _mm_add_epi32(_mm_madd_epi16(v1_l, v2_l), _mm_madd_epi16(v1_r, v2_r)));
+  }
+
+  // Now we can treat the four registers (sum1_vec, sum2_vec, sumsq2_vec,
+  // cross_vec)
+  // as holding 4 32-bit elements each, which we want to sum horizontally.
+  // We do this by transposing and then summing vertically.
+  __m128i tmp_0 = _mm_unpacklo_epi32(sum1_vec, sum2_vec);
+  __m128i tmp_1 = _mm_unpackhi_epi32(sum1_vec, sum2_vec);
+  __m128i tmp_2 = _mm_unpacklo_epi32(sumsq2_vec, cross_vec);
+  __m128i tmp_3 = _mm_unpackhi_epi32(sumsq2_vec, cross_vec);
+
+  __m128i tmp_4 = _mm_unpacklo_epi64(tmp_0, tmp_2);
+  __m128i tmp_5 = _mm_unpackhi_epi64(tmp_0, tmp_2);
+  __m128i tmp_6 = _mm_unpacklo_epi64(tmp_1, tmp_3);
+  __m128i tmp_7 = _mm_unpackhi_epi64(tmp_1, tmp_3);
+
+  __m128i res =
+      _mm_add_epi32(_mm_add_epi32(tmp_4, tmp_5), _mm_add_epi32(tmp_6, tmp_7));
+
+  int sum1 = _mm_extract_epi32(res, 0);
+  int sum2 = _mm_extract_epi32(res, 1);
+  int sumsq2 = _mm_extract_epi32(res, 2);
+  int cross = _mm_extract_epi32(res, 3);
+
+  int var2 = sumsq2 * MATCH_SZ_SQ - sum2 * sum2;
+  int cov = cross * MATCH_SZ_SQ - sum1 * sum2;
+  return cov / sqrt((double)var2);
+}