1 files changed, 146 insertions, 0 deletions
diff --git a/src/dsp/arm/average_blend_neon.cc b/src/dsp/arm/average_blend_neon.cc
new file mode 100644
index 0000000..834e8b4
--- /dev/null
+++ b/src/dsp/arm/average_blend_neon.cc
@@ -0,0 +1,146 @@
+// Copyright 2019 The libgav1 Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "src/dsp/average_blend.h"
+#include "src/utils/cpu.h"
+
+#if LIBGAV1_ENABLE_NEON
+
+#include <arm_neon.h>
+
+#include <cassert>
+#include <cstddef>
+#include <cstdint>
+
+#include "src/dsp/arm/common_neon.h"
+#include "src/dsp/constants.h"
+#include "src/dsp/dsp.h"
+#include "src/utils/common.h"
+
+namespace libgav1 {
+namespace dsp {
+namespace {
+
+constexpr int kInterPostRoundBit =
+    kInterRoundBitsVertical - kInterRoundBitsCompoundVertical;
+
+inline uint8x8_t AverageBlend8Row(const int16_t* prediction_0,
+                                  const int16_t* prediction_1) {
+  const int16x8_t pred0 = vld1q_s16(prediction_0);
+  const int16x8_t pred1 = vld1q_s16(prediction_1);
+  const int16x8_t res = vaddq_s16(pred0, pred1);
+  return vqrshrun_n_s16(res, kInterPostRoundBit + 1);
+}
+
+inline void AverageBlendLargeRow(const int16_t* prediction_0,
+                                 const int16_t* prediction_1, const int width,
+                                 uint8_t* dest) {
+  int x = width;
+  do {
+    const int16x8_t pred_00 = vld1q_s16(prediction_0);
+    const int16x8_t pred_01 = vld1q_s16(prediction_1);
+    prediction_0 += 8;
+    prediction_1 += 8;
+    const int16x8_t res0 = vaddq_s16(pred_00, pred_01);
+    const uint8x8_t res_out0 = vqrshrun_n_s16(res0, kInterPostRoundBit + 1);
+    const int16x8_t pred_10 = vld1q_s16(prediction_0);
+    const int16x8_t pred_11 = vld1q_s16(prediction_1);
+    prediction_0 += 8;
+    prediction_1 += 8;
+    const int16x8_t res1 = vaddq_s16(pred_10, pred_11);
+    const uint8x8_t res_out1 = vqrshrun_n_s16(res1, kInterPostRoundBit + 1);
+    vst1q_u8(dest, vcombine_u8(res_out0, res_out1));
+    dest += 16;
+    x -= 16;
+  } while (x != 0);
+}
+
+void AverageBlend_NEON(const void* prediction_0, const void* prediction_1,
+                       const int width, const int height, void* const dest,
+                       const ptrdiff_t dest_stride) {
+  auto* dst = static_cast<uint8_t*>(dest);
+  const auto* pred_0 = static_cast<const int16_t*>(prediction_0);
+  const auto* pred_1 = static_cast<const int16_t*>(prediction_1);
+  int y = height;
+
+  if (width == 4) {
+    do {
+      const uint8x8_t result = AverageBlend8Row(pred_0, pred_1);
+      pred_0 += 8;
+      pred_1 += 8;
+
+      StoreLo4(dst, result);
+      dst += dest_stride;
+      StoreHi4(dst, result);
+      dst += dest_stride;
+      y -= 2;
+    } while (y != 0);
+    return;
+  }
+
+  if (width == 8) {
+    do {
+      vst1_u8(dst, AverageBlend8Row(pred_0, pred_1));
+      dst += dest_stride;
+      pred_0 += 8;
+      pred_1 += 8;
+
+      vst1_u8(dst, AverageBlend8Row(pred_0, pred_1));
+      dst += dest_stride;
+      pred_0 += 8;
+      pred_1 += 8;
+
+      y -= 2;
+    } while (y != 0);
+    return;
+  }
+
+  do {
+    AverageBlendLargeRow(pred_0, pred_1, width, dst);
+    dst += dest_stride;
+    pred_0 += width;
+    pred_1 += width;
+
+    AverageBlendLargeRow(pred_0, pred_1, width, dst);
+    dst += dest_stride;
+    pred_0 += width;
+    pred_1 += width;
+
+    y -= 2;
+  } while (y != 0);
+}
+
+void Init8bpp() {
+  Dsp* const dsp = dsp_internal::GetWritableDspTable(kBitdepth8);
+  assert(dsp != nullptr);
+  dsp->average_blend = AverageBlend_NEON;
+}
+
+}  // namespace
+
+void AverageBlendInit_NEON() { Init8bpp(); }
+
+}  // namespace dsp
+}  // namespace libgav1
+
+#else  // !LIBGAV1_ENABLE_NEON
+
+namespace libgav1 {
+namespace dsp {
+
+void AverageBlendInit_NEON() {}
+
+}  // namespace dsp
+}  // namespace libgav1
+#endif  // LIBGAV1_ENABLE_NEON