chore: import upstream snapshot with attribution

2026-07-13 13:33:03 +08:00
commit 5b57521aa1
8226 changed files with 3425766 additions and 0 deletions
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+//
+//  ShuffleNetExpr.cpp
+//  MNN
+//  Reference paper: https://arxiv.org/pdf/1707.01083.pdf
+//
+//  Created by MNN on 2019/06/25.
+//  Copyright © 2018, Alibaba Group Holding Limited
+//
+
+#include <map>
+#include "ShuffleNetExpr.hpp"
+#include <MNN/expr/ExprCreator.hpp>
+
+using namespace MNN::Express;
+
+// bottleNeckChannel = outputChannel / narrowRatio
+static VARP shuffleUnit(VARP x, int inputChannel, int outputChannel,
+                        int group, int stride, int narrowRatio) {
+    int bottleNeckChannel = outputChannel / narrowRatio;
+    int branchChannel = outputChannel;
+    if (stride != 1) {
+        branchChannel = outputChannel - inputChannel;
+    }
+    auto y = _Conv(0.0f, 0.0f, x, {inputChannel, bottleNeckChannel}, {1, 1}, VALID, {1, 1}, {1, 1}, group); // Group Conv
+    y = _ChannelShuffle(y, group);
+    y = _Conv(0.0f, 0.0f, y, {bottleNeckChannel, bottleNeckChannel}, {3, 3}, SAME, {stride, stride}, {1, 1}, bottleNeckChannel); // Depthwise Conv
+    y = _Conv(0.0f, 0.0f, y, {bottleNeckChannel, branchChannel}, {1, 1}, VALID, {1, 1}, {1, 1}, group); // Group Conv
+    if (stride != 1) {
+        x = _AvePool(x, {3, 3}, {2, 2}, SAME);
+        y = _Concat({x, y}, 1); // concat on channel axis (NCHW)
+    } else {
+        y = _Add(x, y);
+    }
+    return y;
+}
+
+static VARP shuffleBlock(VARP x, int inputChannel, int outputChannel,
+                         int group, int stride, int narrowRatio, int number) {
+    x = shuffleUnit(x, inputChannel, outputChannel, group, stride, narrowRatio);
+    for (int i = 1; i < number; ++i) {
+        x = shuffleUnit(x, outputChannel, outputChannel, group, 1, narrowRatio);
+    }
+    return x;
+}
+
+VARP shuffleNetExpr(int group, int numClass) {
+    std::map<int, std::vector<int>> groupMap = {
+        {1, {144, 288, 576}},
+        {2, {200, 400, 800}},
+        {3, {240, 480, 960}},
+        {4, {272, 544, 1088}},
+        {8, {384, 768, 1536}}
+    };
+    int outputChannelStage2 = groupMap[group][0];
+    int outputChannelStage3 = groupMap[group][1];
+    int outputChannelStage4 = groupMap[group][2];
+    // Net Construction
+    auto x = _Input({1, 3, 224, 224}, NC4HW4);
+    x = _Conv(0.0f, 0.0f, x, {3, 24}, {3, 3}, SAME, {2, 2}, {1, 1}, 1);
+    x = _MaxPool(x, {3, 3}, {2, 2}, SAME);
+    x = shuffleBlock(x, 24, outputChannelStage2, group, 2, 4, 4);
+    x = shuffleBlock(x, outputChannelStage2, outputChannelStage3, group, 2, 4, 8);
+    x = shuffleBlock(x, outputChannelStage3, outputChannelStage4, group, 2, 4, 4);
+    x = _AvePool(x, {7, 7}, {1, 1}, VALID);
+    x = _Conv(0.0f, 0.0f, x, {outputChannelStage4, numClass}, {1, 1}, VALID, {1, 1}, {1, 1}, 1); // replace FC with Conv1x1
+    return x;
+}