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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+//
+//  SoftmaxGrad.cpp
+//  MNN
+//
+//  Created by MNN on 2019/04/22.
+//  Copyright © 2018, Alibaba Group Holding Limited
+//
+
+#include "SoftmaxGrad.hpp"
+#include "core/Macro.h"
+#include <MNN/expr/ExprCreator.hpp>
+using namespace std;
+namespace MNN {
+using namespace MNN::Express;
+
+class SoftmaxGrad : public OpGrad {
+public:
+    SoftmaxGrad() {
+        mType = NO_LINEAR;
+    }
+    virtual std::vector<Express::VARP> onGrad(Express::EXPRP expr,
+                                              const std::vector<Express::VARP>& backwardOutput) override {
+        MNN_ASSERT(expr->inputs().size() == 1 && backwardOutput.size() == 1);
+        auto input = expr->inputs()[0];
+        auto info = input->getInfo();
+        auto gradSoftmax = backwardOutput[0];
+        if (nullptr == info) {
+            return {};
+        }
+        auto axis = expr->get()->main_as_Axis()->axis();
+        if (axis < 0) {
+            axis = axis + info->dim.size();
+        }
+        auto softmax = Express::Variable::create(expr, 0);
+        auto originOrder = info->order;
+        if (originOrder == NC4HW4) {
+            gradSoftmax = _Convert(gradSoftmax, NCHW);
+            softmax = _Convert(softmax, NCHW);
+        }
+        auto sumAxis = _ReduceSum(softmax * gradSoftmax, {axis}, true);
+        auto inputGrad = (gradSoftmax - sumAxis) * softmax;
+        if (originOrder == NC4HW4) {
+            inputGrad = _Convert(inputGrad, NC4HW4);
+        }
+        return {inputGrad};
+    }
+};
+static void _create() {
+    static SoftmaxGrad _c;
+    OpGrad::insert(OpType_Softmax, &_c);
+
+}
+
+REGISTER_GRAD(SoftmaxGrad_cpp, _create);
+};
+