"wait add generic"

paddle/framework/backward.cc

@@ -52,6 +52,11 @@ static std::shared_ptr<OperatorBase> EmptyOp() {
 static std::shared_ptr<OperatorBase> BackwardImpl(
     const OperatorBase& forwardOp,
     std::unordered_set<std::string>& no_grad_names, size_t& uniq_id) {
+  // struct OpIdentity {
+  //   size_t local_op_id;
+  //   size_t op_output_offset;
+  // };
+
   if (AllInSet(forwardOp.inputs_, OperatorBase::GRAD_VAR_SUFFIX(),
                no_grad_names)) {
     return EmptyOp();
@@ -66,44 +71,51 @@ static std::shared_ptr<OperatorBase> BackwardImpl(
     return EmptyOp();
   }
 
-  auto* net = new NetOp();
+  // auto* net = new NetOp();
 
   if (forwardOp.IsNetOp()) {
     //! TODO(dzh)
-    std::unordered_map<std::string, int> dup_output;
-    std::unordered_map<std::string, std::vector<int>> dup_output_ops;
-    //    const unsigned uniq_id_local = uniq_id;
-    int op_id_offset = 0;
+    std::unordered_map<std::string /*var name*/,
+                       std::vector<size_t> /*op offs et*/>
+        dup_output_ops;
+    size_t local_op_id = 0;
     // Because it is a net op, it can static_cast.
     auto& forwardNet = static_cast<const NetOp&>(forwardOp);
 
+    // travesal subnet/op
     for (auto& fwd : forwardNet.ops_) {
       auto bwd = Backward(*fwd, no_grad_names);
       net->AddOp(bwd);
       for (size_t i = 0; i < bwd->outputs_.size(); ++i) {
-        bwd->outputs_[i] += OperatorBase::EMPTY_VAR_NAME();
-        if (dup_output.find(bwd->inputs_[i]) == dup_output.end()) {
-          dup_output[bwd->inputs_[i]] = 1;
-          dup_output_ops[bwd->inputs_[i]] = std::vector<int>{op_id_offset++};
-        } else {
-          dup_output[bwd->inputs_[i]]++;
-          dup_output_ops[bwd->inputs_[i]].emplace_back(op_id_offset++);
-        }
+        dup_output_ops[bwd->outputs_[i]].emplace_back(local_op_id);
       }
+      local_op_id++;
     }
-    for (auto dup : dup_output) {
-      if (dup.second == 1) continue;
-      auto op_ids = dup_output_ops.at(dup.first);
-      for (auto& op_id : op_ids) {
-        auto& op_ptr = net->ops_[op_id];
-        for (size_t i = 0; i < op_ptr->inputs_.size(); ++i) {
-          if (op_ptr->inputs_[i] == dup.first) {
-            // unique the duplicate name
-            op_ptr->inputs_[i] += std::to_string(uniq_id++);
-            // TODO(dzh): need a generic add op here
-          }
-        }
+    // unique the duplicate name
+    auto uid = uniq_id++;
+    std::unordered_map<size_t, OperatorBase> insert_postion;
+    for (auto& dup_output_op : dup_output_ops) {
+      std::string& name = dup_output_op.first;
+      auto& dup_op = dup_output_op.second;
+      if (dup_op.size() == 1) continue;
+      std::vector<std::string> dup_outputs;
+
+      for (size_t i = 0; i < dup_op.size(); ++i) {
+        auto op_offset = dup_op[i];
+        net->ops_[op_offset].Rename(
+            name,
+            name + "@RENAME@" + std::to_string(uid) + "@" + std::to_string(i));
       }
+      insert_postion[op_offset] =
+          OpRegistry::CreateOp("Add", {}, {dup_op->inputs_}, {});
+      net->AddOp("Add");
+      net->AddOp();
+      // process shared variable
+      // while(dup_op.size()) {
+      //
+      //  AddOp(OpRegistry::CreateOp("generic_add", {dup_outputs},
+      //                             {dup_op->inputs_}, {}));
+      //}
     }
 
   } else {

paddle/framework/net.cc

@@ -74,5 +74,27 @@ std::string NetOp::DebugString() const {
 
 bool NetOp::IsNetOp() const { return true; }
 
+void NetOp::Rename(const std::unordered_map<
+                       std::string, std::vector<OpIdentity>>& dup_output_ops,
+                   size_t& uniq_id) {
+  for (auto& op : ops_) {
+    if (op->isNetOp()) {
+      op->Rename(dup_output_ops, uniq_id);
+    }
+    for (size_t i = 0; i < op->outputs_.size(); ++i) {
+      std::vector<std::string> dup_outputs;
+      if (op->outputs_[i] ==) {
+        op->outputs_[i] += std::to_string(uniq_id++);
+        dup_outputs.push_back(op->outputs_[i]);
+      }
+      // add duplicate output together. replace with AddOp
+      if (dup_outputs.size() >= 2) {
+        AddOp(OpRegistry::CreateOp("generic_add", {dup_outputs}, {op->inputs_},
+                                   {}));
+      }
+    }
+  }
+}
+
 }  // namespace framework
 }  // namespace paddle

paddle/framework/net.h

@@ -49,6 +49,11 @@ class NetOp : public OperatorBase {
     }
   }
 
+  /**
+   * @brief rename duplicated output gradient name in Net
+   */
+  bool Rename(size_t& uniq_id);
+
   /**
    * @brief Run the network.
    *
@@ -88,5 +93,9 @@ class NetOp : public OperatorBase {
   }
 };
 
+/**
+ * @brief Identify operator in local Net. used in backward
+ */
+
 }  // namespace framework
 }  // namespace paddle

paddle/framework/operator.cc

@@ -99,5 +99,11 @@ std::string OperatorBase::DebugString() const {
   return ss.str();
 }
 
+void OperatorBase::Rename(const std::string& old_name,
+                          const std::string& new_name) {
+  std::replace(inputs_.begin(), inputs_.end(), old_name, new_name);
+  std::replace(outputs_.begin(), outputs_.end(), old_name, new_name);
+}
+
 }  // namespace framework
 }  // namespace paddle

paddle/framework/operator.h

@@ -14,6 +14,7 @@ limitations under the License. */
 
 #pragma once
 
+#include <algorithm>
 #include <boost/variant.hpp>
 #include <string>
 #include <unordered_map>
@@ -95,6 +96,9 @@ class OperatorBase {
 
   virtual bool IsNetOp() const { return false; }
 
+  /// rename inputs outputs name
+  void Rename(const std::string& old_name, const std::string& new_name);
+
   //! Get a input with argument's name described in `op_proto`
   const std::string& Input(const std::string& name) const;
   //! Get a input which has multiple variables.
@@ -108,7 +112,13 @@ class OperatorBase {
 
  public:
   std::string type_;
+  // NOTE: in case of OpGrad, inputs_ contains:
+  // I (Inputs)
+  // O (Outputs)
+  // OG (Output Gradients)
   std::vector<std::string> inputs_;
+  // NOTE: in case of OpGrad, outputs_ contains
+  // IG (Inputs Gradients)
   std::vector<std::string> outputs_;
   AttributeMap attrs_;
   // store the arguments' offset described in op_desc.